task_name
string
rows
int64
cols
int64
rules
string
visual_elements
string
initial_board
string
solution
string
initial_observation
string
solution_reference
string
description
string
title
string
hint
string
sudoku_normal_hard_100
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.94.5..16.2..19...1.54..9..4.9...1...5.14.69....97.4355...9.7..98......12....1..9
394857216628319547175426983439685172752143698861972435513298764987564321246731859
. 9 4 . 5 . . 1 6 . 2 . . 1 9 . . . 1 . 5 4 . . 9 . . 4 . 9 . . . 1 . . . 5 . 1 4 . 6 9 . . . . 9 7 . 4 3 5 5 . . . 9 . 7 . . 9 8 . . . . . . 1 2 . . . . 1 . . 9
3 9 4 8 5 7 2 1 6 6 2 8 3 1 9 5 4 7 1 7 5 4 2 6 9 8 3 4 3 9 6 8 5 1 7 2 7 5 2 1 4 3 6 9 8 8 6 1 9 7 2 4 3 5 5 1 3 2 9 8 7 6 4 9 8 7 5 6 4 3 2 1 2 4 6 7 3 1 8 5 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4732_hard
394857216628319547175426983439685172752143698861972435513298764987564321246731859 #1 Extreme (31972) bf Hidden Single: r2c5=1 Hidden Single: r6c4=9 Hidden Single: r6c7=4 Hidden Single: r4c7=1 Locked Candidates Type 1 (Pointing): 4 in b3 => r2c3<>4 Hidden Rectangle: 1/6 in r6c23,r7c23 => r7c3<>6 Bru...
sudoku_normal_extremely_hard_100
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
....5..16.2...9...1.54..9..4.9.......5.14........7..355...9.7...8......12....1...
394857216628319547175426983439685172752143698861972435513298764987564321246731859
. . . . 5 . . 1 6 . 2 . . . 9 . . . 1 . 5 4 . . 9 . . 4 . 9 . . . . . . . 5 . 1 4 . . . . . . . . 7 . . 3 5 5 . . . 9 . 7 . . . 8 . . . . . . 1 2 . . . . 1 . . .
3 9 4 8 5 7 2 1 6 6 2 8 3 1 9 5 4 7 1 7 5 4 2 6 9 8 3 4 3 9 6 8 5 1 7 2 7 5 2 1 4 3 6 9 8 8 6 1 9 7 2 4 3 5 5 1 3 2 9 8 7 6 4 9 8 7 5 6 4 3 2 1 2 4 6 7 3 1 8 5 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4732_hard
394857216628319547175426983439685172752143698861972435513298764987564321246731859 #1 Extreme (31972) bf Hidden Single: r2c5=1 Hidden Single: r6c4=9 Hidden Single: r6c7=4 Hidden Single: r4c7=1 Locked Candidates Type 1 (Pointing): 4 in b3 => r2c3<>4 Hidden Rectangle: 1/6 in r6c23,r7c23 => r7c3<>6 Bru...
sudoku_normal_hard_101
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..1..7..2....1..5.9..3..1...95683...624179....834526...4.79...1.19..4.7.5..8.19..
851967432436218759972345168795683214624179385183452697348796521219534876567821943
. . 1 . . 7 . . 2 . . . . 1 . . 5 . 9 . . 3 . . 1 . . . 9 5 6 8 3 . . . 6 2 4 1 7 9 . . . . 8 3 4 5 2 6 . . . 4 . 7 9 . . . 1 . 1 9 . . 4 . 7 . 5 . . 8 . 1 9 . .
8 5 1 9 6 7 4 3 2 4 3 6 2 1 8 7 5 9 9 7 2 3 4 5 1 6 8 7 9 5 6 8 3 2 1 4 6 2 4 1 7 9 3 8 5 1 8 3 4 5 2 6 9 7 3 4 8 7 9 6 5 2 1 2 1 9 5 3 4 8 7 6 5 6 7 8 2 1 9 4 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4370_hard
851967432436218759972345168795683214624179385183452697348796521219534876567821943 #1 Extreme (23442) bf Brute Force: r5c5=7 Hidden Single: r7c4=7 Locked Candidates Type 1 (Pointing): 7 in b4 => r2c1<>7 Forcing Net Contradiction in r3 => r4c8<>8 r4c8=8 r4c8<>1 r4c1=1 r5c2<>1 r5c2=2 r5c3<>2 r5c3=4 r3c3<>4 ...
sudoku_normal_extremely_hard_101
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..1..7..2....1..5.9..3..1...956.3...6.........83.526...4......1..9..4.7.5..8..9..
851967432436218759972345168795683214624179385183452697348796521219534876567821943
. . 1 . . 7 . . 2 . . . . 1 . . 5 . 9 . . 3 . . 1 . . . 9 5 6 . 3 . . . 6 . . . . . . . . . 8 3 . 5 2 6 . . . 4 . . . . . . 1 . . 9 . . 4 . 7 . 5 . . 8 . . 9 . .
8 5 1 9 6 7 4 3 2 4 3 6 2 1 8 7 5 9 9 7 2 3 4 5 1 6 8 7 9 5 6 8 3 2 1 4 6 2 4 1 7 9 3 8 5 1 8 3 4 5 2 6 9 7 3 4 8 7 9 6 5 2 1 2 1 9 5 3 4 8 7 6 5 6 7 8 2 1 9 4 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4370_hard
851967432436218759972345168795683214624179385183452697348796521219534876567821943 #1 Extreme (23442) bf Brute Force: r5c5=7 Hidden Single: r7c4=7 Locked Candidates Type 1 (Pointing): 7 in b4 => r2c1<>7 Forcing Net Contradiction in r3 => r4c8<>8 r4c8=8 r4c8<>1 r4c1=1 r5c2<>1 r5c2=2 r5c3<>2 r5c3=4 r3c3<>4 ...
sudoku_normal_hard_102
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7....8..3..5....6....65..1.3....4..8..7936.2..2.81.3...48..97..9.........73.....9
716298543835471962492653817369524178187936425524817396248369751951782634673145289
7 . . . . 8 . . 3 . . 5 . . . . 6 . . . . 6 5 . . 1 . 3 . . . . 4 . . 8 . . 7 9 3 6 . 2 . . 2 . 8 1 . 3 . . . 4 8 . . 9 7 . . 9 . . . . . . . . . 7 3 . . . . . 9
7 1 6 2 9 8 5 4 3 8 3 5 4 7 1 9 6 2 4 9 2 6 5 3 8 1 7 3 6 9 5 2 4 1 7 8 1 8 7 9 3 6 4 2 5 5 2 4 8 1 7 3 9 6 2 4 8 3 6 9 7 5 1 9 5 1 7 8 2 6 3 4 6 7 3 1 4 5 2 8 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4294_hard
716298543835471962492653817369524178187936425524817396248369751951782634673145289 #1 Extreme (39912) bf Locked Candidates Type 1 (Pointing): 7 in b3 => r6c9<>7 Locked Candidates Type 1 (Pointing): 8 in b3 => r89c7<>8 Brute Force: r5c5=3 Locked Candidates Type 1 (Pointing): 8 in b5 => r89c4<>8 Brute Force...
sudoku_normal_extremely_hard_102
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7....8..3..5....6....65..1.3....4..8..7....2..2..1.3...48..97..9.........73.....9
716298543835471962492653817369524178187936425524817396248369751951782634673145289
7 . . . . 8 . . 3 . . 5 . . . . 6 . . . . 6 5 . . 1 . 3 . . . . 4 . . 8 . . 7 . . . . 2 . . 2 . . 1 . 3 . . . 4 8 . . 9 7 . . 9 . . . . . . . . . 7 3 . . . . . 9
7 1 6 2 9 8 5 4 3 8 3 5 4 7 1 9 6 2 4 9 2 6 5 3 8 1 7 3 6 9 5 2 4 1 7 8 1 8 7 9 3 6 4 2 5 5 2 4 8 1 7 3 9 6 2 4 8 3 6 9 7 5 1 9 5 1 7 8 2 6 3 4 6 7 3 1 4 5 2 8 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4294_hard
716298543835471962492653817369524178187936425524817396248369751951782634673145289 #1 Extreme (39912) bf Locked Candidates Type 1 (Pointing): 7 in b3 => r6c9<>7 Locked Candidates Type 1 (Pointing): 8 in b3 => r89c7<>8 Brute Force: r5c5=3 Locked Candidates Type 1 (Pointing): 8 in b5 => r89c4<>8 Brute Force...
sudoku_normal_hard_103
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....4..2..812..3..7..689..5....92......8.....6..3...4.3..7.5....18.....4....3.2.
153794862698125437274368951517649283349281675862537194936472518721856349485913726
. . . . . 4 . . 2 . . 8 1 2 . . 3 . . 7 . . 6 8 9 . . 5 . . . . 9 2 . . . . . . 8 . . . . . 6 . . 3 . . . 4 . 3 . . 7 . 5 . . . . 1 8 . . . . . 4 . . . . 3 . 2 .
1 5 3 7 9 4 8 6 2 6 9 8 1 2 5 4 3 7 2 7 4 3 6 8 9 5 1 5 1 7 6 4 9 2 8 3 3 4 9 2 8 1 6 7 5 8 6 2 5 3 7 1 9 4 9 3 6 4 7 2 5 1 8 7 2 1 8 5 6 3 4 9 4 8 5 9 1 3 7 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7559_hard
153794862698125437274368951517649283349281675862537194936472518721856349485913726 #1 Extreme (24512) bf AIC: 3/4 4- r3c3 =4= r3c8 -4- r2c7 =4= r8c7 =3= r8c9 -3- r4c9 =3= r4c3 -3 => r3c3<>3, r4c3<>4 Brute Force: r5c5=8 Hidden Single: r3c6=8 Finned X-Wing: 8 c29 r49 fr7c9 => r9c7<>8 Forcing Net Contradicti...
sudoku_normal_extremely_hard_103
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....4..2..81...3..7..6.9..5....92............6..3...4.3..7.5....18.....4....3.2.
153794862698125437274368951517649283349281675862537194936472518721856349485913726
. . . . . 4 . . 2 . . 8 1 . . . 3 . . 7 . . 6 . 9 . . 5 . . . . 9 2 . . . . . . . . . . . . 6 . . 3 . . . 4 . 3 . . 7 . 5 . . . . 1 8 . . . . . 4 . . . . 3 . 2 .
1 5 3 7 9 4 8 6 2 6 9 8 1 2 5 4 3 7 2 7 4 3 6 8 9 5 1 5 1 7 6 4 9 2 8 3 3 4 9 2 8 1 6 7 5 8 6 2 5 3 7 1 9 4 9 3 6 4 7 2 5 1 8 7 2 1 8 5 6 3 4 9 4 8 5 9 1 3 7 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7559_hard
153794862698125437274368951517649283349281675862537194936472518721856349485913726 #1 Extreme (24512) bf AIC: 3/4 4- r3c3 =4= r3c8 -4- r2c7 =4= r8c7 =3= r8c9 -3- r4c9 =3= r4c3 -3 => r3c3<>3, r4c3<>4 Brute Force: r5c5=8 Hidden Single: r3c6=8 Finned X-Wing: 8 c29 r49 fr7c9 => r9c7<>8 Forcing Net Contradicti...
sudoku_normal_hard_104
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7..4...95.5.7.82....2.5....5...8.7..9.36.4581.1...5...2...4.95....5.3....45....6.
786432195159768234432159678564381729923674581817295346271846953698523417345917862
7 . . 4 . . . 9 5 . 5 . 7 . 8 2 . . . . 2 . 5 . . . . 5 . . . 8 . 7 . . 9 . 3 6 . 4 5 8 1 . 1 . . . 5 . . . 2 . . . 4 . 9 5 . . . . 5 . 3 . . . . 4 5 . . . . 6 .
7 8 6 4 3 2 1 9 5 1 5 9 7 6 8 2 3 4 4 3 2 1 5 9 6 7 8 5 6 4 3 8 1 7 2 9 9 2 3 6 7 4 5 8 1 8 1 7 2 9 5 3 4 6 2 7 1 8 4 6 9 5 3 6 9 8 5 2 3 4 1 7 3 4 5 9 1 7 8 6 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_6940_hard
786432195159768234432159678564381729923674581817295346271846953698523417345917862 #1 Extreme (39004) bf Brute Force: r5c7=5 Hidden Single: r1c9=5 Hidden Single: r6c6=5 Hidden Single: r7c8=5 Brute Force: r5c6=4 Locked Candidates Type 1 (Pointing): 7 in b5 => r89c5<>7 Discontinuous Nice Loop: 9 r4c2 ...
sudoku_normal_extremely_hard_104
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7..4...9..5.7.82....2.5....5...8.7....36....1.1.......2...4.9.....5.3....45....6.
786432195159768234432159678564381729923674581817295346271846953698523417345917862
7 . . 4 . . . 9 . . 5 . 7 . 8 2 . . . . 2 . 5 . . . . 5 . . . 8 . 7 . . . . 3 6 . . . . 1 . 1 . . . . . . . 2 . . . 4 . 9 . . . . . 5 . 3 . . . . 4 5 . . . . 6 .
7 8 6 4 3 2 1 9 5 1 5 9 7 6 8 2 3 4 4 3 2 1 5 9 6 7 8 5 6 4 3 8 1 7 2 9 9 2 3 6 7 4 5 8 1 8 1 7 2 9 5 3 4 6 2 7 1 8 4 6 9 5 3 6 9 8 5 2 3 4 1 7 3 4 5 9 1 7 8 6 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_6940_hard
786432195159768234432159678564381729923674581817295346271846953698523417345917862 #1 Extreme (39004) bf Brute Force: r5c7=5 Hidden Single: r1c9=5 Hidden Single: r6c6=5 Hidden Single: r7c8=5 Brute Force: r5c6=4 Locked Candidates Type 1 (Pointing): 7 in b5 => r89c5<>7 Discontinuous Nice Loop: 9 r4c2 ...
sudoku_normal_hard_105
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7...15..3..24...1..1...25....79...51...18...6.6125..9.17...9.4...9......42.7.....
794615283532478619816392574287946351945183726361257498173569842659824137428731965
7 . . . 1 5 . . 3 . . 2 4 . . . 1 . . 1 . . . 2 5 . . . . 7 9 . . . 5 1 . . . 1 8 . . . 6 . 6 1 2 5 . . 9 . 1 7 . . . 9 . 4 . . . 9 . . . . . . 4 2 . 7 . . . . .
7 9 4 6 1 5 2 8 3 5 3 2 4 7 8 6 1 9 8 1 6 3 9 2 5 7 4 2 8 7 9 4 6 3 5 1 9 4 5 1 8 3 7 2 6 3 6 1 2 5 7 4 9 8 1 7 3 5 6 9 8 4 2 6 5 9 8 2 4 1 3 7 4 2 8 7 3 1 9 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9172_hard
794615283532478619816392574287946351945183726361257498173569842659824137428731965 #1 Extreme (20538) bf Finned X-Wing: 2 c69 r38 fr7c9 => r8c78<>2 Brute Force: r5c4=1 Hidden Single: r1c5=1 Hidden Single: r6c5=5 Locked Candidates Type 1 (Pointing): 2 in b2 => r3c89<>2 Locked Candidates Type 1 (Pointing...
sudoku_normal_extremely_hard_105
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7....5..3..24...1..1....5....79...51....8...6.612...9.17...9.4...9......42.7.....
794615283532478619816392574287946351945183726361257498173569842659824137428731965
7 . . . . 5 . . 3 . . 2 4 . . . 1 . . 1 . . . . 5 . . . . 7 9 . . . 5 1 . . . . 8 . . . 6 . 6 1 2 . . . 9 . 1 7 . . . 9 . 4 . . . 9 . . . . . . 4 2 . 7 . . . . .
7 9 4 6 1 5 2 8 3 5 3 2 4 7 8 6 1 9 8 1 6 3 9 2 5 7 4 2 8 7 9 4 6 3 5 1 9 4 5 1 8 3 7 2 6 3 6 1 2 5 7 4 9 8 1 7 3 5 6 9 8 4 2 6 5 9 8 2 4 1 3 7 4 2 8 7 3 1 9 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9172_hard
794615283532478619816392574287946351945183726361257498173569842659824137428731965 #1 Extreme (20538) bf Finned X-Wing: 2 c69 r38 fr7c9 => r8c78<>2 Brute Force: r5c4=1 Hidden Single: r1c5=1 Hidden Single: r6c5=5 Locked Candidates Type 1 (Pointing): 2 in b2 => r3c89<>2 Locked Candidates Type 1 (Pointing...
sudoku_normal_hard_106
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7...816.........51.91........9.47...2.861.4...4..28..39...74.3..1.....4.4....68..
753481692824963751691752384569347128238619475147528963982174536316895247475236819
7 . . . 8 1 6 . . . . . . . . . 5 1 . 9 1 . . . . . . . . 9 . 4 7 . . . 2 . 8 6 1 . 4 . . . 4 . . 2 8 . . 3 9 . . . 7 4 . 3 . . 1 . . . . . 4 . 4 . . . . 6 8 . .
7 5 3 4 8 1 6 9 2 8 2 4 9 6 3 7 5 1 6 9 1 7 5 2 3 8 4 5 6 9 3 4 7 1 2 8 2 3 8 6 1 9 4 7 5 1 4 7 5 2 8 9 6 3 9 8 2 1 7 4 5 3 6 3 1 6 8 9 5 2 4 7 4 7 5 2 3 6 8 1 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3591_hard
753481692824963751691752384569347128238619475147528963982174536316895247475236819 #1 Extreme (30012) bf Locked Candidates Type 1 (Pointing): 8 in b3 => r3c13<>8 Locked Candidates Type 1 (Pointing): 6 in b9 => r4c9<>6 Brute Force: r5c3=8 Brute Force: r5c5=1 Grouped Discontinuous Nice Loop: 5 r3c3 -5- r1c2...
sudoku_normal_extremely_hard_106
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7...816.........51.9.........9.47...2..6..4...4..28..39...74.3..1.....4.4....68..
753481692824963751691752384569347128238619475147528963982174536316895247475236819
7 . . . 8 1 6 . . . . . . . . . 5 1 . 9 . . . . . . . . . 9 . 4 7 . . . 2 . . 6 . . 4 . . . 4 . . 2 8 . . 3 9 . . . 7 4 . 3 . . 1 . . . . . 4 . 4 . . . . 6 8 . .
7 5 3 4 8 1 6 9 2 8 2 4 9 6 3 7 5 1 6 9 1 7 5 2 3 8 4 5 6 9 3 4 7 1 2 8 2 3 8 6 1 9 4 7 5 1 4 7 5 2 8 9 6 3 9 8 2 1 7 4 5 3 6 3 1 6 8 9 5 2 4 7 4 7 5 2 3 6 8 1 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3591_hard
753481692824963751691752384569347128238619475147528963982174536316895247475236819 #1 Extreme (30012) bf Locked Candidates Type 1 (Pointing): 8 in b3 => r3c13<>8 Locked Candidates Type 1 (Pointing): 6 in b9 => r4c9<>6 Brute Force: r5c3=8 Brute Force: r5c5=1 Grouped Discontinuous Nice Loop: 5 r3c3 -5- r1c2...
sudoku_normal_hard_107
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
5....2.6..1.65.4..2.67......6..2.854...5.6.39.5.4896..4.1.6..8..8......66.5...1..
574192368819653427236748915967321854148576239352489671421965783783214596695837142
5 . . . . 2 . 6 . . 1 . 6 5 . 4 . . 2 . 6 7 . . . . . . 6 . . 2 . 8 5 4 . . . 5 . 6 . 3 9 . 5 . 4 8 9 6 . . 4 . 1 . 6 . . 8 . . 8 . . . . . . 6 6 . 5 . . . 1 . .
5 7 4 1 9 2 3 6 8 8 1 9 6 5 3 4 2 7 2 3 6 7 4 8 9 1 5 9 6 7 3 2 1 8 5 4 1 4 8 5 7 6 2 3 9 3 5 2 4 8 9 6 7 1 4 2 1 9 6 5 7 8 3 7 8 3 2 1 4 5 9 6 6 9 5 8 3 7 1 4 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3398_hard
574192368819653427236748915967321854148576239352489671421965783783214596695837142 #1 Extreme (21512) bf Hidden Single: r8c9=6 Hidden Single: r1c1=5 Brute Force: r5c4=5 Hidden Single: r4c8=5 Hidden Single: r5c6=6 Hidden Single: r2c4=6 Hidden Single: r3c3=6 Locked Candidates Type 1 (Pointing): 1 i...
sudoku_normal_extremely_hard_107
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....2.6..1..5.4..2..7......6..2.8.4.......39.5..896..4.1.6..8..8.......6.5...1..
574192368819653427236748915967321854148576239352489671421965783783214596695837142
. . . . . 2 . 6 . . 1 . . 5 . 4 . . 2 . . 7 . . . . . . 6 . . 2 . 8 . 4 . . . . . . . 3 9 . 5 . . 8 9 6 . . 4 . 1 . 6 . . 8 . . 8 . . . . . . . 6 . 5 . . . 1 . .
5 7 4 1 9 2 3 6 8 8 1 9 6 5 3 4 2 7 2 3 6 7 4 8 9 1 5 9 6 7 3 2 1 8 5 4 1 4 8 5 7 6 2 3 9 3 5 2 4 8 9 6 7 1 4 2 1 9 6 5 7 8 3 7 8 3 2 1 4 5 9 6 6 9 5 8 3 7 1 4 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3398_hard
574192368819653427236748915967321854148576239352489671421965783783214596695837142 #1 Extreme (21512) bf Hidden Single: r8c9=6 Hidden Single: r1c1=5 Brute Force: r5c4=5 Hidden Single: r4c8=5 Hidden Single: r5c6=6 Hidden Single: r2c4=6 Hidden Single: r3c3=6 Locked Candidates Type 1 (Pointing): 1 i...
sudoku_normal_hard_108
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.8.6...7..74...9...3..8...2.2..7..5..6854...1.57..6.9..423......13..5...89..1...3
289634175674251938135987462421879356968543721357126894542398617713465289896712543
. 8 . 6 . . . 7 . . 7 4 . . . 9 . . . 3 . . 8 . . . 2 . 2 . . 7 . . 5 . . 6 8 5 4 . . . 1 . 5 7 . . 6 . 9 . . 4 2 3 . . . . . . 1 3 . . 5 . . . 8 9 . . 1 . . . 3
2 8 9 6 3 4 1 7 5 6 7 4 2 5 1 9 3 8 1 3 5 9 8 7 4 6 2 4 2 1 8 7 9 3 5 6 9 6 8 5 4 3 7 2 1 3 5 7 1 2 6 8 9 4 5 4 2 3 9 8 6 1 7 7 1 3 4 6 5 2 8 9 8 9 6 7 1 2 5 4 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3585_hard
289634175674251938135987462421879356968543721357126894542398617713465289896712543 #1 Extreme (26340) bf Forcing Net Contradiction in r3 => r7c9<>6 r7c9=6 (r7c1<>6) (r7c5<>6 r7c5=9 r7c1<>9) (r7c5<>6 r8c5=6 r8c1<>6) r7c9<>9 r8c9=9 r8c1<>9 r8c1=7 r7c1<>7 r7c1=5 r3c1<>5 r7c9=6 (r7c9<>7) r7c9<>9 r8c9=9 (r8c1<>9 r8c1=...
sudoku_normal_extremely_hard_108
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
...6...7...4...9...3..8...2....7..5...8.4...1.....6.9..423......13..5...8...1...3
289634175674251938135987462421879356968543721357126894542398617713465289896712543
. . . 6 . . . 7 . . . 4 . . . 9 . . . 3 . . 8 . . . 2 . . . . 7 . . 5 . . . 8 . 4 . . . 1 . . . . . 6 . 9 . . 4 2 3 . . . . . . 1 3 . . 5 . . . 8 . . . 1 . . . 3
2 8 9 6 3 4 1 7 5 6 7 4 2 5 1 9 3 8 1 3 5 9 8 7 4 6 2 4 2 1 8 7 9 3 5 6 9 6 8 5 4 3 7 2 1 3 5 7 1 2 6 8 9 4 5 4 2 3 9 8 6 1 7 7 1 3 4 6 5 2 8 9 8 9 6 7 1 2 5 4 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3585_hard
289634175674251938135987462421879356968543721357126894542398617713465289896712543 #1 Extreme (26340) bf Forcing Net Contradiction in r3 => r7c9<>6 r7c9=6 (r7c1<>6) (r7c5<>6 r7c5=9 r7c1<>9) (r7c5<>6 r8c5=6 r8c1<>6) r7c9<>9 r8c9=9 r8c1<>9 r8c1=7 r7c1<>7 r7c1=5 r3c1<>5 r7c9=6 (r7c9<>7) r7c9<>9 r8c9=9 (r8c1<>9 r8c1=...
sudoku_normal_hard_109
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8.5..1.4..13...2.1...63...4.......2..34..7...79....8.....36....4.9..235..7..1.9
368254917475139862912876354843567291291348576657921438729413685184695723536782149
. . 8 . 5 . . 1 . 4 . . 1 3 . . . 2 . 1 . . . 6 3 . . . 4 . . . . . . . 2 . . 3 4 . . 7 . . . 7 9 . . . . 8 . . . . . 3 6 . . . . 4 . 9 . . 2 3 5 . . 7 . . 1 . 9
3 6 8 2 5 4 9 1 7 4 7 5 1 3 9 8 6 2 9 1 2 8 7 6 3 5 4 8 4 3 5 6 7 2 9 1 2 9 1 3 4 8 5 7 6 6 5 7 9 2 1 4 3 8 7 2 9 4 1 3 6 8 5 1 8 4 6 9 5 7 2 3 5 3 6 7 8 2 1 4 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7547_hard
368254917475139862912876354843567291291348576657921438729413685184695723536782149 #1 Extreme (20530) bf Brute Force: r5c4=3 Hidden Single: r2c5=3 Skyscraper: 3 in r8c9,r9c3 (connected by r4c39) => r8c12,r9c8<>3 Hidden Single: r8c9=3 Grouped AIC: 8/9 9- r2c6 =9= r1c6 =4= r9c6 -4- r9c8 -8- r89c7 =8= r2c7 -...
sudoku_normal_extremely_hard_109
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8.5..1.4..1....2.1...63...4.......2...4..7...79....8.....36....4.9..2.5..7....9
368254917475139862912876354843567291291348576657921438729413685184695723536782149
. . 8 . 5 . . 1 . 4 . . 1 . . . . 2 . 1 . . . 6 3 . . . 4 . . . . . . . 2 . . . 4 . . 7 . . . 7 9 . . . . 8 . . . . . 3 6 . . . . 4 . 9 . . 2 . 5 . . 7 . . . . 9
3 6 8 2 5 4 9 1 7 4 7 5 1 3 9 8 6 2 9 1 2 8 7 6 3 5 4 8 4 3 5 6 7 2 9 1 2 9 1 3 4 8 5 7 6 6 5 7 9 2 1 4 3 8 7 2 9 4 1 3 6 8 5 1 8 4 6 9 5 7 2 3 5 3 6 7 8 2 1 4 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7547_hard
368254917475139862912876354843567291291348576657921438729413685184695723536782149 #1 Extreme (20530) bf Brute Force: r5c4=3 Hidden Single: r2c5=3 Skyscraper: 3 in r8c9,r9c3 (connected by r4c39) => r8c12,r9c8<>3 Hidden Single: r8c9=3 Grouped AIC: 8/9 9- r2c6 =9= r1c6 =4= r9c6 -4- r9c8 -8- r89c7 =8= r2c7 -...
sudoku_normal_hard_110
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
71.92.6.4....14..22.46.7.9..2.4....5.46172..3..7...42.67.24......27.1.464.1.692.7
718925634963814572254637198129483765546172983837596421675248319392751846481369257
7 1 . 9 2 . 6 . 4 . . . . 1 4 . . 2 2 . 4 6 . 7 . 9 . . 2 . 4 . . . . 5 . 4 6 1 7 2 . . 3 . . 7 . . . 4 2 . 6 7 . 2 4 . . . . . . 2 7 . 1 . 4 6 4 . 1 . 6 9 2 . 7
7 1 8 9 2 5 6 3 4 9 6 3 8 1 4 5 7 2 2 5 4 6 3 7 1 9 8 1 2 9 4 8 3 7 6 5 5 4 6 1 7 2 9 8 3 8 3 7 5 9 6 4 2 1 6 7 5 2 4 8 3 1 9 3 9 2 7 5 1 8 4 6 4 8 1 3 6 9 2 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9917_hard
718925634963814572254637198129483765546172983837596421675248319392751846481369257 #1 Extreme (21124) bf Hidden Single: r1c5=2 Hidden Single: r6c8=2 Hidden Single: r2c6=4 Hidden Single: r1c9=4 Hidden Single: r5c2=4 Hidden Single: r8c3=2 Hidden Single: r9c5=6 Hidden Single: r7c2=7 Hidden Single...
sudoku_normal_extremely_hard_110
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
71.9..6......1...22.46...9..2.4....5....72..3..7...4..6..2........7.1.464.1..9..7
718925634963814572254637198129483765546172983837596421675248319392751846481369257
7 1 . 9 . . 6 . . . . . . 1 . . . 2 2 . 4 6 . . . 9 . . 2 . 4 . . . . 5 . . . . 7 2 . . 3 . . 7 . . . 4 . . 6 . . 2 . . . . . . . . 7 . 1 . 4 6 4 . 1 . . 9 . . 7
7 1 8 9 2 5 6 3 4 9 6 3 8 1 4 5 7 2 2 5 4 6 3 7 1 9 8 1 2 9 4 8 3 7 6 5 5 4 6 1 7 2 9 8 3 8 3 7 5 9 6 4 2 1 6 7 5 2 4 8 3 1 9 3 9 2 7 5 1 8 4 6 4 8 1 3 6 9 2 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9917_hard
718925634963814572254637198129483765546172983837596421675248319392751846481369257 #1 Extreme (21124) bf Hidden Single: r1c5=2 Hidden Single: r6c8=2 Hidden Single: r2c6=4 Hidden Single: r1c9=4 Hidden Single: r5c2=4 Hidden Single: r8c3=2 Hidden Single: r9c5=6 Hidden Single: r7c2=7 Hidden Single...
sudoku_normal_hard_111
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7....9..69.5..2..441..3.....5.......3478916252....5..7.2...476...49....26.....4..
783549216965182374412637598856723941347891625291465837128354769534976182679218453
7 . . . . 9 . . 6 9 . 5 . . 2 . . 4 4 1 . . 3 . . . . . 5 . . . . . . . 3 4 7 8 9 1 6 2 5 2 . . . . 5 . . 7 . 2 . . . 4 7 6 . . . 4 9 . . . . 2 6 . . . . . 4 . .
7 8 3 5 4 9 2 1 6 9 6 5 1 8 2 3 7 4 4 1 2 6 3 7 5 9 8 8 5 6 7 2 3 9 4 1 3 4 7 8 9 1 6 2 5 2 9 1 4 6 5 8 3 7 1 2 8 3 5 4 7 6 9 5 3 4 9 7 6 1 8 2 6 7 9 2 1 8 4 5 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4615_hard
783549216965182374412637598856723941347891625291465837128354769534976182679218453 #1 Extreme (45378) bf Brute Force: r5c5=9 Locked Candidates Type 2 (Claiming): 4 in r5 => r4c1,r6c2<>4 Brute Force: r5c2=4 Hidden Single: r3c1=4 Forcing Net Contradiction in r3c6 => r2c5<>6 r2c5=6 r3c6<>6 r2c5=6 (r2c4<>...
sudoku_normal_extremely_hard_111
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7....9..69.5..2..4.1..3.....5.........78...2.2....5..7.2...476...49....26.....4..
783549216965182374412637598856723941347891625291465837128354769534976182679218453
7 . . . . 9 . . 6 9 . 5 . . 2 . . 4 . 1 . . 3 . . . . . 5 . . . . . . . . . 7 8 . . . 2 . 2 . . . . 5 . . 7 . 2 . . . 4 7 6 . . . 4 9 . . . . 2 6 . . . . . 4 . .
7 8 3 5 4 9 2 1 6 9 6 5 1 8 2 3 7 4 4 1 2 6 3 7 5 9 8 8 5 6 7 2 3 9 4 1 3 4 7 8 9 1 6 2 5 2 9 1 4 6 5 8 3 7 1 2 8 3 5 4 7 6 9 5 3 4 9 7 6 1 8 2 6 7 9 2 1 8 4 5 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4615_hard
783549216965182374412637598856723941347891625291465837128354769534976182679218453 #1 Extreme (45378) bf Brute Force: r5c5=9 Locked Candidates Type 2 (Claiming): 4 in r5 => r4c1,r6c2<>4 Brute Force: r5c2=4 Hidden Single: r3c1=4 Forcing Net Contradiction in r3c6 => r2c5<>6 r2c5=6 r3c6<>6 r2c5=6 (r2c4<>...
sudoku_normal_hard_112
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2......8..4.2..9.5..1..2.....5...12.52.816..1...62.8..9.273.6.6.....92.2..6..8.7
721936458364825791589147236876594312952381674143762589498273165617458923235619847
. 2 . . . . . . 8 . . 4 . 2 . . 9 . 5 . . 1 . . 2 . . . . . 5 . . . 1 2 . 5 2 . 8 1 6 . . 1 . . . 6 2 . 8 . . 9 . 2 7 3 . 6 . 6 . . . . . 9 2 . 2 . . 6 . . 8 . 7
7 2 1 9 3 6 4 5 8 3 6 4 8 2 5 7 9 1 5 8 9 1 4 7 2 3 6 8 7 6 5 9 4 3 1 2 9 5 2 3 8 1 6 7 4 1 4 3 7 6 2 5 8 9 4 9 8 2 7 3 1 6 5 6 1 7 4 5 8 9 2 3 2 3 5 6 1 9 8 4 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7885_hard
721936458364825791589147236876594312952381674143762589498273165617458923235619847 #1 Extreme (33984) bf Brute Force: r4c9=2 Hidden Single: r8c8=2 Hidden Single: r7c4=2 Hidden Single: r2c5=2 Locked Candidates Type 1 (Pointing): 8 in b8 => r8c23<>8 Finned Swordfish: 1 r147 c378 fr7c9 => r9c8<>1 Finne...
sudoku_normal_extremely_hard_112
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2......8..4....9.5..1..2.....5......52.816..1...62....9..73.6.6.....9..2..6..8.7
721936458364825791589147236876594312952381674143762589498273165617458923235619847
. 2 . . . . . . 8 . . 4 . . . . 9 . 5 . . 1 . . 2 . . . . . 5 . . . . . . 5 2 . 8 1 6 . . 1 . . . 6 2 . . . . 9 . . 7 3 . 6 . 6 . . . . . 9 . . 2 . . 6 . . 8 . 7
7 2 1 9 3 6 4 5 8 3 6 4 8 2 5 7 9 1 5 8 9 1 4 7 2 3 6 8 7 6 5 9 4 3 1 2 9 5 2 3 8 1 6 7 4 1 4 3 7 6 2 5 8 9 4 9 8 2 7 3 1 6 5 6 1 7 4 5 8 9 2 3 2 3 5 6 1 9 8 4 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7885_hard
721936458364825791589147236876594312952381674143762589498273165617458923235619847 #1 Extreme (33984) bf Brute Force: r4c9=2 Hidden Single: r8c8=2 Hidden Single: r7c4=2 Hidden Single: r2c5=2 Locked Candidates Type 1 (Pointing): 8 in b8 => r8c23<>8 Finned Swordfish: 1 r147 c378 fr7c9 => r9c8<>1 Finne...
sudoku_normal_hard_113
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.4...63....893...4...41..5..3.6..9..8....327...2...5.32.........9..6.1..7....9.35
149756382658932714327418659531627948864593271972184563285371496493865127716249835
. 4 . . . 6 3 . . . . 8 9 3 . . . 4 . . . 4 1 . . 5 . . 3 . 6 . . 9 . . 8 . . . . 3 2 7 . . . 2 . . . 5 . 3 2 . . . . . . . . . 9 . . 6 . 1 . . 7 . . . . 9 . 3 5
1 4 9 7 5 6 3 8 2 6 5 8 9 3 2 7 1 4 3 2 7 4 1 8 6 5 9 5 3 1 6 2 7 9 4 8 8 6 4 5 9 3 2 7 1 9 7 2 1 8 4 5 6 3 2 8 5 3 7 1 4 9 6 4 9 3 8 6 5 1 2 7 7 1 6 2 4 9 8 3 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3441_hard
149756382658932714327418659531627948864593271972184563285371496493865127716249835 #1 Extreme (24726) bf Hidden Single: r2c5=3 Hidden Single: r6c9=3 Brute Force: r5c7=2 Hidden Single: r6c7=5 Locked Candidates Type 1 (Pointing): 4 in b6 => r78c8<>4 Locked Candidates Type 1 (Pointing): 2 in b9 => r8c46<>...
sudoku_normal_extremely_hard_113
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.4...63....89....4...41..5..3.6..9..8....3.7...2......2.........9..6.1..7....9.35
149756382658932714327418659531627948864593271972184563285371496493865127716249835
. 4 . . . 6 3 . . . . 8 9 . . . . 4 . . . 4 1 . . 5 . . 3 . 6 . . 9 . . 8 . . . . 3 . 7 . . . 2 . . . . . . 2 . . . . . . . . . 9 . . 6 . 1 . . 7 . . . . 9 . 3 5
1 4 9 7 5 6 3 8 2 6 5 8 9 3 2 7 1 4 3 2 7 4 1 8 6 5 9 5 3 1 6 2 7 9 4 8 8 6 4 5 9 3 2 7 1 9 7 2 1 8 4 5 6 3 2 8 5 3 7 1 4 9 6 4 9 3 8 6 5 1 2 7 7 1 6 2 4 9 8 3 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3441_hard
149756382658932714327418659531627948864593271972184563285371496493865127716249835 #1 Extreme (24726) bf Hidden Single: r2c5=3 Hidden Single: r6c9=3 Brute Force: r5c7=2 Hidden Single: r6c7=5 Locked Candidates Type 1 (Pointing): 4 in b6 => r78c8<>4 Locked Candidates Type 1 (Pointing): 2 in b9 => r8c46<>...
sudoku_normal_hard_114
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8...7..3..1...6..9......54...3..2....27.......6.43.7..534.8...49.1...36....2.4.
168495732354127968792863415476938521583271694921654387215349876849716253637582149
. . 8 . . . 7 . . 3 . . 1 . . . 6 . . 9 . . . . . . 5 4 . . . 3 . . 2 . . . . 2 7 . . . . . . . 6 . 4 3 . 7 . . 5 3 4 . 8 . . . 4 9 . 1 . . . 3 6 . . . . 2 . 4 .
1 6 8 4 9 5 7 3 2 3 5 4 1 2 7 9 6 8 7 9 2 8 6 3 4 1 5 4 7 6 9 3 8 5 2 1 5 8 3 2 7 1 6 9 4 9 2 1 6 5 4 3 8 7 2 1 5 3 4 9 8 7 6 8 4 9 7 1 6 2 5 3 6 3 7 5 8 2 1 4 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7097_hard
168495732354127968792863415476938521583271694921654387215349876849716253637582149 #1 Extreme (19284) bf Locked Candidates Type 1 (Pointing): 4 in b7 => r12c2<>4 Brute Force: r5c5=7 Finned Swordfish: 7 r249 c234 fr2c6 => r3c4<>7 Locked Candidates Type 1 (Pointing): 7 in b2 => r78c6<>7 Discontinuous Nice L...
sudoku_normal_extremely_hard_114
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8...7..3..1...6..9......54...3..2....2........6.43.7..53..8....9.1....6....2.4.
168495732354127968792863415476938521583271694921654387215349876849716253637582149
. . 8 . . . 7 . . 3 . . 1 . . . 6 . . 9 . . . . . . 5 4 . . . 3 . . 2 . . . . 2 . . . . . . . . 6 . 4 3 . 7 . . 5 3 . . 8 . . . . 9 . 1 . . . . 6 . . . . 2 . 4 .
1 6 8 4 9 5 7 3 2 3 5 4 1 2 7 9 6 8 7 9 2 8 6 3 4 1 5 4 7 6 9 3 8 5 2 1 5 8 3 2 7 1 6 9 4 9 2 1 6 5 4 3 8 7 2 1 5 3 4 9 8 7 6 8 4 9 7 1 6 2 5 3 6 3 7 5 8 2 1 4 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7097_hard
168495732354127968792863415476938521583271694921654387215349876849716253637582149 #1 Extreme (19284) bf Locked Candidates Type 1 (Pointing): 4 in b7 => r12c2<>4 Brute Force: r5c5=7 Finned Swordfish: 7 r249 c234 fr2c6 => r3c4<>7 Locked Candidates Type 1 (Pointing): 7 in b2 => r78c6<>7 Discontinuous Nice L...
sudoku_normal_hard_115
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
....82.6.26.95..1.9...1.2....6.2...141.8396...29.6..84..429..3..3..7....69.3451..
541782963263954817978613245386427591415839672729561384154298736832176459697345128
. . . . 8 2 . 6 . 2 6 . 9 5 . . 1 . 9 . . . 1 . 2 . . . . 6 . 2 . . . 1 4 1 . 8 3 9 6 . . . 2 9 . 6 . . 8 4 . . 4 2 9 . . 3 . . 3 . . 7 . . . . 6 9 . 3 4 5 1 . .
5 4 1 7 8 2 9 6 3 2 6 3 9 5 4 8 1 7 9 7 8 6 1 3 2 4 5 3 8 6 4 2 7 5 9 1 4 1 5 8 3 9 6 7 2 7 2 9 5 6 1 3 8 4 1 5 4 2 9 8 7 3 6 8 3 2 1 7 6 4 5 9 6 9 7 3 4 5 1 2 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4242_hard
541782963263954817978613245386427591415839672729561384154298736832176459697345128 #1 Extreme (23992) bf Hidden Single: r7c5=9 Hidden Single: r4c9=1 Locked Candidates Type 2 (Claiming): 6 in c5 => r4c46,r6c46<>6 Hidden Pair: 6,9 in r46c3 => r46c3<>3, r46c3<>5, r46c3<>7, r4c3<>8 Brute Force: r5c4=8 Forc...
sudoku_normal_extremely_hard_115
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....2.6.26.95..1.9...1.2...........41...96...2.....84..42...3..3..7....69...51..
541782963263954817978613245386427591415839672729561384154298736832176459697345128
. . . . . 2 . 6 . 2 6 . 9 5 . . 1 . 9 . . . 1 . 2 . . . . . . . . . . . 4 1 . . . 9 6 . . . 2 . . . . . 8 4 . . 4 2 . . . 3 . . 3 . . 7 . . . . 6 9 . . . 5 1 . .
5 4 1 7 8 2 9 6 3 2 6 3 9 5 4 8 1 7 9 7 8 6 1 3 2 4 5 3 8 6 4 2 7 5 9 1 4 1 5 8 3 9 6 7 2 7 2 9 5 6 1 3 8 4 1 5 4 2 9 8 7 3 6 8 3 2 1 7 6 4 5 9 6 9 7 3 4 5 1 2 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4242_hard
541782963263954817978613245386427591415839672729561384154298736832176459697345128 #1 Extreme (23992) bf Hidden Single: r7c5=9 Hidden Single: r4c9=1 Locked Candidates Type 2 (Claiming): 6 in c5 => r4c46,r6c46<>6 Hidden Pair: 6,9 in r46c3 => r46c3<>3, r46c3<>5, r46c3<>7, r4c3<>8 Brute Force: r5c4=8 Forc...
sudoku_normal_hard_116
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.26.5....4..2.9..6..98467.......183...89.2..71......6.6...2...4.5...4.....43...7.
826157943417239586539846721965471832348962157172583469681725394753694218294318675
. 2 6 . 5 . . . . 4 . . 2 . 9 . . 6 . . 9 8 4 6 7 . . . . . . . 1 8 3 . . . 8 9 . 2 . . 7 1 . . . . . . 6 . 6 . . . 2 . . . 4 . 5 . . . 4 . . . . . 4 3 . . . 7 .
8 2 6 1 5 7 9 4 3 4 1 7 2 3 9 5 8 6 5 3 9 8 4 6 7 2 1 9 6 5 4 7 1 8 3 2 3 4 8 9 6 2 1 5 7 1 7 2 5 8 3 4 6 9 6 8 1 7 2 5 3 9 4 7 5 3 6 9 4 2 1 8 2 9 4 3 1 8 6 7 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7692_hard
826157943417239586539846721965471832348962157172583469681725394753694218294318675 #1 Extreme (19906) bf Brute Force: r5c6=2 Hidden Single: r2c4=2 Naked Pair: 3,5 in r35c1 => r18c1<>3, r4c1<>5 Grouped Discontinuous Nice Loop: 4 r5c5 -4- r3c5 =4= r3c8 =2= r3c9 -2- r46c9 =2= r6c7 =4= r5c78 -4- r5c5 => r5c5<>4 ...
sudoku_normal_extremely_hard_116
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2..5....4....9..6..98..7.......183...89....71......6.6...2...4.5...4.....43...7.
826157943417239586539846721965471832348962157172583469681725394753694218294318675
. 2 . . 5 . . . . 4 . . . . 9 . . 6 . . 9 8 . . 7 . . . . . . . 1 8 3 . . . 8 9 . . . . 7 1 . . . . . . 6 . 6 . . . 2 . . . 4 . 5 . . . 4 . . . . . 4 3 . . . 7 .
8 2 6 1 5 7 9 4 3 4 1 7 2 3 9 5 8 6 5 3 9 8 4 6 7 2 1 9 6 5 4 7 1 8 3 2 3 4 8 9 6 2 1 5 7 1 7 2 5 8 3 4 6 9 6 8 1 7 2 5 3 9 4 7 5 3 6 9 4 2 1 8 2 9 4 3 1 8 6 7 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7692_hard
826157943417239586539846721965471832348962157172583469681725394753694218294318675 #1 Extreme (19906) bf Brute Force: r5c6=2 Hidden Single: r2c4=2 Naked Pair: 3,5 in r35c1 => r18c1<>3, r4c1<>5 Grouped Discontinuous Nice Loop: 4 r5c5 -4- r3c5 =4= r3c8 =2= r3c9 -2- r46c9 =2= r6c7 =4= r5c78 -4- r5c5 => r5c5<>4 ...
sudoku_normal_hard_117
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
3...7.52.......867..75..31...143.9.2.....9.46.9.....53..2.1.6.5.4.6....86....8...
386971524915243867427586319561437982238159746794862153872314695143695278659728431
3 . . . 7 . 5 2 . . . . . . . 8 6 7 . . 7 5 . . 3 1 . . . 1 4 3 . 9 . 2 . . . . . 9 . 4 6 . 9 . . . . . 5 3 . . 2 . 1 . 6 . 5 . 4 . 6 . . . . 8 6 . . . . 8 . . .
3 8 6 9 7 1 5 2 4 9 1 5 2 4 3 8 6 7 4 2 7 5 8 6 3 1 9 5 6 1 4 3 7 9 8 2 2 3 8 1 5 9 7 4 6 7 9 4 8 6 2 1 5 3 8 7 2 3 1 4 6 9 5 1 4 3 6 9 5 2 7 8 6 5 9 7 2 8 4 3 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8206_hard
386971524915243867427586319561437982238159746794862153872314695143695278659728431 #1 Extreme (15290) bf Locked Candidates Type 1 (Pointing): 3 in b6 => r89c9<>3 Brute Force: r5c9=6 Hidden Single: r6c9=3 Locked Candidates Type 1 (Pointing): 6 in b3 => r2c2356<>6 Locked Candidates Type 1 (Pointing): 1 in b...
sudoku_normal_extremely_hard_117
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
3...7.52.........7..75..31...143.9.2.....9.4..9.....5...2.1...5.4.6.....6....8...
386971524915243867427586319561437982238159746794862153872314695143695278659728431
3 . . . 7 . 5 2 . . . . . . . . . 7 . . 7 5 . . 3 1 . . . 1 4 3 . 9 . 2 . . . . . 9 . 4 . . 9 . . . . . 5 . . . 2 . 1 . . . 5 . 4 . 6 . . . . . 6 . . . . 8 . . .
3 8 6 9 7 1 5 2 4 9 1 5 2 4 3 8 6 7 4 2 7 5 8 6 3 1 9 5 6 1 4 3 7 9 8 2 2 3 8 1 5 9 7 4 6 7 9 4 8 6 2 1 5 3 8 7 2 3 1 4 6 9 5 1 4 3 6 9 5 2 7 8 6 5 9 7 2 8 4 3 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8206_hard
386971524915243867427586319561437982238159746794862153872314695143695278659728431 #1 Extreme (15290) bf Locked Candidates Type 1 (Pointing): 3 in b6 => r89c9<>3 Brute Force: r5c9=6 Hidden Single: r6c9=3 Locked Candidates Type 1 (Pointing): 6 in b3 => r2c2356<>6 Locked Candidates Type 1 (Pointing): 1 in b...
sudoku_normal_hard_118
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.6582.....2.1..65...9.65...25.9.1.6..81.562399.628...5..86.....6.25..3.4.1......6
165827943824139657739465182253941768481756239976283415348672591692518374517394826
. 6 5 8 2 . . . . . 2 . 1 . . 6 5 . . . 9 . 6 5 . . . 2 5 . 9 . 1 . 6 . . 8 1 . 5 6 2 3 9 9 . 6 2 8 . . . 5 . . 8 6 . . . . . 6 . 2 5 . . 3 . 4 . 1 . . . . . . 6
1 6 5 8 2 7 9 4 3 8 2 4 1 3 9 6 5 7 7 3 9 4 6 5 1 8 2 2 5 3 9 4 1 7 6 8 4 8 1 7 5 6 2 3 9 9 7 6 2 8 3 4 1 5 3 4 8 6 7 2 5 9 1 6 9 2 5 1 8 3 7 4 5 1 7 3 9 4 8 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7201_hard
165827943824139657739465182253941768481756239976283415348672591692518374517394826 #1 Extreme (27050) bf Hidden Single: r2c8=5 Hidden Single: r3c5=6 Hidden Single: r1c2=6 Hidden Single: r4c1=2 Hidden Single: r5c3=1 Hidden Single: r4c8=6 Hidden Single: r4c2=5 Hidden Single: r8c4=5 Brute Force: ...
sudoku_normal_extremely_hard_118
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..582.....2.1..6....9..5......9.1....8..562..9.628...5..86.....6.2...3.4.1......6
165827943824139657739465182253941768481756239976283415348672591692518374517394826
. . 5 8 2 . . . . . 2 . 1 . . 6 . . . . 9 . . 5 . . . . . . 9 . 1 . . . . 8 . . 5 6 2 . . 9 . 6 2 8 . . . 5 . . 8 6 . . . . . 6 . 2 . . . 3 . 4 . 1 . . . . . . 6
1 6 5 8 2 7 9 4 3 8 2 4 1 3 9 6 5 7 7 3 9 4 6 5 1 8 2 2 5 3 9 4 1 7 6 8 4 8 1 7 5 6 2 3 9 9 7 6 2 8 3 4 1 5 3 4 8 6 7 2 5 9 1 6 9 2 5 1 8 3 7 4 5 1 7 3 9 4 8 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7201_hard
165827943824139657739465182253941768481756239976283415348672591692518374517394826 #1 Extreme (27050) bf Hidden Single: r2c8=5 Hidden Single: r3c5=6 Hidden Single: r1c2=6 Hidden Single: r4c1=2 Hidden Single: r5c3=1 Hidden Single: r4c8=6 Hidden Single: r4c2=5 Hidden Single: r8c4=5 Brute Force: ...
sudoku_normal_hard_119
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.5..4..7...7..94..8.47.52....61.4....4.976.3..7..5264.7...2.3.4.2.4.....4..5.7.2.
652843179317269485894715263236184597145976832978352641789621354523498716461537928
. 5 . . 4 . . 7 . . . 7 . . 9 4 . . 8 . 4 7 . 5 2 . . . . 6 1 . 4 . . . . 4 . 9 7 6 . 3 . . 7 . . 5 2 6 4 . 7 . . . 2 . 3 . 4 . 2 . 4 . . . . . 4 . . 5 . 7 . 2 .
6 5 2 8 4 3 1 7 9 3 1 7 2 6 9 4 8 5 8 9 4 7 1 5 2 6 3 2 3 6 1 8 4 5 9 7 1 4 5 9 7 6 8 3 2 9 7 8 3 5 2 6 4 1 7 8 9 6 2 1 3 5 4 5 2 3 4 9 8 7 1 6 4 6 1 5 3 7 9 2 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4880_hard
652843179317269485894715263236184597145976832978352641789621354523498716461537928 #1 Extreme (20230) bf Hidden Single: r6c8=4 Hidden Single: r4c6=4 Hidden Single: r3c6=5 Hidden Single: r3c4=7 Hidden Single: r7c1=7 Hidden Single: r3c3=4 Hidden Single: r2c7=4 Hidden Single: r9c1=4 Almost Locked...
sudoku_normal_extremely_hard_119
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.5..4..7...7..9...8.....2....61......4..7..3..7..526......2.3.4.2.4........5.7.2.
652843179317269485894715263236184597145976832978352641789621354523498716461537928
. 5 . . 4 . . 7 . . . 7 . . 9 . . . 8 . . . . . 2 . . . . 6 1 . . . . . . 4 . . 7 . . 3 . . 7 . . 5 2 6 . . . . . . 2 . 3 . 4 . 2 . 4 . . . . . . . . 5 . 7 . 2 .
6 5 2 8 4 3 1 7 9 3 1 7 2 6 9 4 8 5 8 9 4 7 1 5 2 6 3 2 3 6 1 8 4 5 9 7 1 4 5 9 7 6 8 3 2 9 7 8 3 5 2 6 4 1 7 8 9 6 2 1 3 5 4 5 2 3 4 9 8 7 1 6 4 6 1 5 3 7 9 2 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4880_hard
652843179317269485894715263236184597145976832978352641789621354523498716461537928 #1 Extreme (20230) bf Hidden Single: r6c8=4 Hidden Single: r4c6=4 Hidden Single: r3c6=5 Hidden Single: r3c4=7 Hidden Single: r7c1=7 Hidden Single: r3c3=4 Hidden Single: r2c7=4 Hidden Single: r9c1=4 Almost Locked...
sudoku_normal_hard_120
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....2..95...3.....1.7..3...6.41..7...4..89.....6..4..9......5...8.....2.7..6.1..
743182569586934217219756384362419875154378926897625431921847653638591742475263198
. . . . . 2 . . 9 5 . . . 3 . . . . . 1 . 7 . . 3 . . . 6 . 4 1 . . 7 . . . 4 . . 8 9 . . . . . 6 . . 4 . . 9 . . . . . . 5 . . . 8 . . . . . 2 . 7 . . 6 . 1 . .
7 4 3 1 8 2 5 6 9 5 8 6 9 3 4 2 1 7 2 1 9 7 5 6 3 8 4 3 6 2 4 1 9 8 7 5 1 5 4 3 7 8 9 2 6 8 9 7 6 2 5 4 3 1 9 2 1 8 4 7 6 5 3 6 3 8 5 9 1 7 4 2 4 7 5 2 6 3 1 9 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3736_hard
743182569586934217219756384362419875154378926897625431921847653638591742475263198 #1 Extreme (29284) bf Hidden Pair: 1,6 in r7c3,r8c1 => r7c3<>2, r7c3,r8c1<>3, r8c1<>4 Forcing Net Contradiction in r8 => r6c8<>1 r6c8=1 (r5c8<>1) r5c9<>1 r5c1=1 r5c1<>7 r5c5=7 r8c5<>7 r6c8=1 (r1c8<>1 r1c4=1 r8c4<>1) (r5c8<>1) r5...
sudoku_normal_extremely_hard_120
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....2..95...3.....1.7..3...6.41..7...4..8......6..4..9......5...8.....2.7..6.1..
743182569586934217219756384362419875154378926897625431921847653638591742475263198
. . . . . 2 . . 9 5 . . . 3 . . . . . 1 . 7 . . 3 . . . 6 . 4 1 . . 7 . . . 4 . . 8 . . . . . . 6 . . 4 . . 9 . . . . . . 5 . . . 8 . . . . . 2 . 7 . . 6 . 1 . .
7 4 3 1 8 2 5 6 9 5 8 6 9 3 4 2 1 7 2 1 9 7 5 6 3 8 4 3 6 2 4 1 9 8 7 5 1 5 4 3 7 8 9 2 6 8 9 7 6 2 5 4 3 1 9 2 1 8 4 7 6 5 3 6 3 8 5 9 1 7 4 2 4 7 5 2 6 3 1 9 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3736_hard
743182569586934217219756384362419875154378926897625431921847653638591742475263198 #1 Extreme (29284) bf Hidden Pair: 1,6 in r7c3,r8c1 => r7c3<>2, r7c3,r8c1<>3, r8c1<>4 Forcing Net Contradiction in r8 => r6c8<>1 r6c8=1 (r5c8<>1) r5c9<>1 r5c1=1 r5c1<>7 r5c5=7 r8c5<>7 r6c8=1 (r1c8<>1 r1c4=1 r8c4<>1) (r5c8<>1) r5...
sudoku_normal_hard_121
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.5....67...9.....28....1.4.7....8...4..3.521...2.9........5...6.....7.3....8.34..
253489671149736852867521943731268594496375218582194367314952786928647135675813429
. 5 . . . . 6 7 . . . 9 . . . . . 2 8 . . . . 1 . 4 . 7 . . . . 8 . . . 4 . . 3 . 5 2 1 . . . 2 . 9 . . . . . . . . 5 . . . 6 . . . . . 7 . 3 . . . . 8 . 3 4 . .
2 5 3 4 8 9 6 7 1 1 4 9 7 3 6 8 5 2 8 6 7 5 2 1 9 4 3 7 3 1 2 6 8 5 9 4 4 9 6 3 7 5 2 1 8 5 8 2 1 9 4 3 6 7 3 1 4 9 5 2 7 8 6 9 2 8 6 4 7 1 3 5 6 7 5 8 1 3 4 2 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5121_hard
253489671149736852867521943731268594496375218582194367314952786928647135675813429 #1 Extreme (39944) bf Locked Candidates Type 1 (Pointing): 9 in b4 => r789c2<>9 Almost Locked Set XY-Wing: A=r1c13469 {123489}, B=r34589c5 {123467}, C=r2c8,r3c79 {3589}, X,Y=3,8, Z=2,4 => r1c5<>2, r1c5<>4 Brute Force: r5c6=5 N...
sudoku_normal_extremely_hard_121
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.5....67...9.....28....1.4.7....8...4..3...1...2.9........5...6.....7.3....8.34..
253489671149736852867521943731268594496375218582194367314952786928647135675813429
. 5 . . . . 6 7 . . . 9 . . . . . 2 8 . . . . 1 . 4 . 7 . . . . 8 . . . 4 . . 3 . . . 1 . . . 2 . 9 . . . . . . . . 5 . . . 6 . . . . . 7 . 3 . . . . 8 . 3 4 . .
2 5 3 4 8 9 6 7 1 1 4 9 7 3 6 8 5 2 8 6 7 5 2 1 9 4 3 7 3 1 2 6 8 5 9 4 4 9 6 3 7 5 2 1 8 5 8 2 1 9 4 3 6 7 3 1 4 9 5 2 7 8 6 9 2 8 6 4 7 1 3 5 6 7 5 8 1 3 4 2 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5121_hard
253489671149736852867521943731268594496375218582194367314952786928647135675813429 #1 Extreme (39944) bf Locked Candidates Type 1 (Pointing): 9 in b4 => r789c2<>9 Almost Locked Set XY-Wing: A=r1c13469 {123489}, B=r34589c5 {123467}, C=r2c8,r3c79 {3589}, X,Y=3,8, Z=2,4 => r1c5<>2, r1c5<>4 Brute Force: r5c6=5 N...
sudoku_normal_hard_122
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....54....98....3.4..3.86....5..798.92687....7..9...61....8.3.93..1.6..2.43....1
783265419629841573541739862416523798392687145875194326167958234938412657254376981
. . . . . 5 4 . . . . 9 8 . . . . 3 . 4 . . 3 . 8 6 . . . . 5 . . 7 9 8 . 9 2 6 8 7 . . . . 7 . . 9 . . . 6 1 . . . . 8 . 3 . 9 3 . . 1 . 6 . . 2 . 4 3 . . . . 1
7 8 3 2 6 5 4 1 9 6 2 9 8 4 1 5 7 3 5 4 1 7 3 9 8 6 2 4 1 6 5 2 3 7 9 8 3 9 2 6 8 7 1 4 5 8 7 5 1 9 4 3 2 6 1 6 7 9 5 8 2 3 4 9 3 8 4 1 2 6 5 7 2 5 4 3 7 6 9 8 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5280_hard
783265419629841573541739862416523798392687145875194326167958234938412657254376981 #1 Extreme (25748) bf Brute Force: r5c5=8 Hidden Single: r5c6=7 Forcing Net Contradiction in c8 => r4c9<>4 r4c9=4 (r6c8<>4 r8c8=4 r8c8<>5) (r5c8<>4) r5c9<>4 (r5c9=5 r5c2<>5) (r5c9=5 r8c9<>5) r5c1=4 r5c1<>9 r8c1=9 r8c1<>5 r8c3=5...
sudoku_normal_extremely_hard_122
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....54....98....3.4..3..6....5..79...26......7..9...61....8.3..3..1.6..2.43....1
783265419629841573541739862416523798392687145875194326167958234938412657254376981
. . . . . 5 4 . . . . 9 8 . . . . 3 . 4 . . 3 . . 6 . . . . 5 . . 7 9 . . . 2 6 . . . . . . 7 . . 9 . . . 6 1 . . . . 8 . 3 . . 3 . . 1 . 6 . . 2 . 4 3 . . . . 1
7 8 3 2 6 5 4 1 9 6 2 9 8 4 1 5 7 3 5 4 1 7 3 9 8 6 2 4 1 6 5 2 3 7 9 8 3 9 2 6 8 7 1 4 5 8 7 5 1 9 4 3 2 6 1 6 7 9 5 8 2 3 4 9 3 8 4 1 2 6 5 7 2 5 4 3 7 6 9 8 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5280_hard
783265419629841573541739862416523798392687145875194326167958234938412657254376981 #1 Extreme (25748) bf Brute Force: r5c5=8 Hidden Single: r5c6=7 Forcing Net Contradiction in c8 => r4c9<>4 r4c9=4 (r6c8<>4 r8c8=4 r8c8<>5) (r5c8<>4) r5c9<>4 (r5c9=5 r5c2<>5) (r5c9=5 r8c9<>5) r5c1=4 r5c1<>9 r8c1=9 r8c1<>5 r8c3=5...
sudoku_normal_hard_123
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..1.3.8..9....2.6..2......427..5..3...467...8...2..7...1..69.....7..56..6..3.7.5.
561734829948512367723986514279458136154673298836291745315869472497125683682347951
. . 1 . 3 . 8 . . 9 . . . . 2 . 6 . . 2 . . . . . . 4 2 7 . . 5 . . 3 . . . 4 6 7 . . . 8 . . . 2 . . 7 . . . 1 . . 6 9 . . . . . 7 . . 5 6 . . 6 . . 3 . 7 . 5 .
5 6 1 7 3 4 8 2 9 9 4 8 5 1 2 3 6 7 7 2 3 9 8 6 5 1 4 2 7 9 4 5 8 1 3 6 1 5 4 6 7 3 2 9 8 8 3 6 2 9 1 7 4 5 3 1 5 8 6 9 4 7 2 4 9 7 1 2 5 6 8 3 6 8 2 3 4 7 9 5 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3989_hard
561734829948512367723986514279458136154673298836291745315869472497125683682347951 #1 Extreme (16140) bf Discontinuous Nice Loop: 5 r1c9 -5- r6c9 =5= r5c7 =2= r5c8 -2- r1c8 =2= r1c9 => r1c9<>5 Brute Force: r5c5=7 Hidden Single: r4c2=7 Skyscraper: 7 in r2c4,r9c6 (connected by r29c9) => r13c6,r7c4<>7 Hidden...
sudoku_normal_extremely_hard_123
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..1.3.8..9....2.6..2......42...5..3...4.....8...2..7...1..69.....7..56..6..3...5.
561734829948512367723986514279458136154673298836291745315869472497125683682347951
. . 1 . 3 . 8 . . 9 . . . . 2 . 6 . . 2 . . . . . . 4 2 . . . 5 . . 3 . . . 4 . . . . . 8 . . . 2 . . 7 . . . 1 . . 6 9 . . . . . 7 . . 5 6 . . 6 . . 3 . . . 5 .
5 6 1 7 3 4 8 2 9 9 4 8 5 1 2 3 6 7 7 2 3 9 8 6 5 1 4 2 7 9 4 5 8 1 3 6 1 5 4 6 7 3 2 9 8 8 3 6 2 9 1 7 4 5 3 1 5 8 6 9 4 7 2 4 9 7 1 2 5 6 8 3 6 8 2 3 4 7 9 5 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3989_hard
561734829948512367723986514279458136154673298836291745315869472497125683682347951 #1 Extreme (16140) bf Discontinuous Nice Loop: 5 r1c9 -5- r6c9 =5= r5c7 =2= r5c8 -2- r1c8 =2= r1c9 => r1c9<>5 Brute Force: r5c5=7 Hidden Single: r4c2=7 Skyscraper: 7 in r2c4,r9c6 (connected by r29c9) => r13c6,r7c4<>7 Hidden...
sudoku_normal_hard_124
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
5.6.....7.9.5..3..3....2.......2..7..65..12.8..96..4.1.4.2...1.6..9.45...5..8.7.4
516349827298517346374862195183425679465791238729638451847256913631974582952183764
5 . 6 . . . . . 7 . 9 . 5 . . 3 . . 3 . . . . 2 . . . . . . . 2 . . 7 . . 6 5 . . 1 2 . 8 . . 9 6 . . 4 . 1 . 4 . 2 . . . 1 . 6 . . 9 . 4 5 . . . 5 . . 8 . 7 . 4
5 1 6 3 4 9 8 2 7 2 9 8 5 1 7 3 4 6 3 7 4 8 6 2 1 9 5 1 8 3 4 2 5 6 7 9 4 6 5 7 9 1 2 3 8 7 2 9 6 3 8 4 5 1 8 4 7 2 5 6 9 1 3 6 3 1 9 7 4 5 8 2 9 5 2 1 8 3 7 6 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8294_hard
516349827298517346374862195183425679465791238729638451847256913631974582952183764 #1 Extreme (26842) bf Brute Force: r5c3=5 Hidden Single: r9c2=5 Forcing Net Contradiction in r5c1 => r5c5<>7 r5c5=7 (r5c5<>9 r4c6=9 r4c6<>5 r4c9=5 r6c8<>5) (r6c5<>7) (r6c6<>7) r5c4<>7 r3c4=7 r2c6<>7 r7c6=7 r7c6<>5 r7c5=5 r6c5<>...
sudoku_normal_extremely_hard_124
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
5.6.....7.9.5..3..3....2.......2..7......1..8..96..4...4.2...1.6..9.45......8.7.4
516349827298517346374862195183425679465791238729638451847256913631974582952183764
5 . 6 . . . . . 7 . 9 . 5 . . 3 . . 3 . . . . 2 . . . . . . . 2 . . 7 . . . . . . 1 . . 8 . . 9 6 . . 4 . . . 4 . 2 . . . 1 . 6 . . 9 . 4 5 . . . . . . 8 . 7 . 4
5 1 6 3 4 9 8 2 7 2 9 8 5 1 7 3 4 6 3 7 4 8 6 2 1 9 5 1 8 3 4 2 5 6 7 9 4 6 5 7 9 1 2 3 8 7 2 9 6 3 8 4 5 1 8 4 7 2 5 6 9 1 3 6 3 1 9 7 4 5 8 2 9 5 2 1 8 3 7 6 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8294_hard
516349827298517346374862195183425679465791238729638451847256913631974582952183764 #1 Extreme (26842) bf Brute Force: r5c3=5 Hidden Single: r9c2=5 Forcing Net Contradiction in r5c1 => r5c5<>7 r5c5=7 (r5c5<>9 r4c6=9 r4c6<>5 r4c9=5 r6c8<>5) (r6c5<>7) (r6c6<>7) r5c4<>7 r3c4=7 r2c6<>7 r7c6=7 r7c6<>5 r7c5=5 r6c5<>...
sudoku_normal_hard_125
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
8...23....3...6.9...25..3..3.7.6.5..1...359766..7...43.8.6...394..3...1...3..76..
816923457534876192972541368397468521148235976625719843781654239469382715253197684
8 . . . 2 3 . . . . 3 . . . 6 . 9 . . . 2 5 . . 3 . . 3 . 7 . 6 . 5 . . 1 . . . 3 5 9 7 6 6 . . 7 . . . 4 3 . 8 . 6 . . . 3 9 4 . . 3 . . . 1 . . . 3 . . 7 6 . .
8 1 6 9 2 3 4 5 7 5 3 4 8 7 6 1 9 2 9 7 2 5 4 1 3 6 8 3 9 7 4 6 8 5 2 1 1 4 8 2 3 5 9 7 6 6 2 5 7 1 9 8 4 3 7 8 1 6 5 4 2 3 9 4 6 9 3 8 2 7 1 5 2 5 3 1 9 7 6 8 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7441_hard
816923457534876192972541368397468521148235976625719843781654239469382715253197684 #1 Extreme (42092) bf Brute Force: r5c7=9 Hidden Single: r5c8=7 Locked Candidates Type 2 (Claiming): 3 in r5 => r4c4,r6c5<>3 Forcing Net Contradiction in c4 => r9c9<>2 r9c9=2 (r9c1<>2) (r9c8<>2 r4c8=2 r4c2<>2) (r9c2<>2) (r9c...
sudoku_normal_extremely_hard_125
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
8...23....3...6.9...25..3....7.6.5..1....5..6...7...4..8......94......1...3..76..
816923457534876192972541368397468521148235976625719843781654239469382715253197684
8 . . . 2 3 . . . . 3 . . . 6 . 9 . . . 2 5 . . 3 . . . . 7 . 6 . 5 . . 1 . . . . 5 . . 6 . . . 7 . . . 4 . . 8 . . . . . . 9 4 . . . . . . 1 . . . 3 . . 7 6 . .
8 1 6 9 2 3 4 5 7 5 3 4 8 7 6 1 9 2 9 7 2 5 4 1 3 6 8 3 9 7 4 6 8 5 2 1 1 4 8 2 3 5 9 7 6 6 2 5 7 1 9 8 4 3 7 8 1 6 5 4 2 3 9 4 6 9 3 8 2 7 1 5 2 5 3 1 9 7 6 8 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7441_hard
816923457534876192972541368397468521148235976625719843781654239469382715253197684 #1 Extreme (42092) bf Brute Force: r5c7=9 Hidden Single: r5c8=7 Locked Candidates Type 2 (Claiming): 3 in r5 => r4c4,r6c5<>3 Forcing Net Contradiction in c4 => r9c9<>2 r9c9=2 (r9c1<>2) (r9c8<>2 r4c8=2 r4c2<>2) (r9c2<>2) (r9c...
sudoku_normal_hard_126
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..6..9.2..4.36.5..1..........8..5..23...468...6.1.87..6......89..5..72......8....
586479123249361578173852946718935462352746891964128735627514389835697214491283657
. . 6 . . 9 . 2 . . 4 . 3 6 . 5 . . 1 . . . . . . . . . . 8 . . 5 . . 2 3 . . . 4 6 8 . . . 6 . 1 . 8 7 . . 6 . . . . . . 8 9 . . 5 . . 7 2 . . . . . . 8 . . . .
5 8 6 4 7 9 1 2 3 2 4 9 3 6 1 5 7 8 1 7 3 8 5 2 9 4 6 7 1 8 9 3 5 4 6 2 3 5 2 7 4 6 8 9 1 9 6 4 1 2 8 7 3 5 6 2 7 5 1 4 3 8 9 8 3 5 6 9 7 2 1 4 4 9 1 2 8 3 6 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4223_hard
586479123249361578173852946718935462352746891964128735627514389835697214491283657 #1 Extreme (31346) bf Locked Candidates Type 1 (Pointing): 5 in b9 => r9c4<>5 Locked Candidates Type 1 (Pointing): 7 in b9 => r9c123<>7 Hidden Pair: 5,7 in r9c89 => r9c89<>1, r9c89<>3, r9c89<>4, r9c89<>6 Brute Force: r5c7=8 ...
sudoku_normal_extremely_hard_126
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..6..9.2..4.36.5..1..........8..5..23...4.....6.1..7..6......89..5..72......8....
586479123249361578173852946718935462352746891964128735627514389835697214491283657
. . 6 . . 9 . 2 . . 4 . 3 6 . 5 . . 1 . . . . . . . . . . 8 . . 5 . . 2 3 . . . 4 . . . . . 6 . 1 . . 7 . . 6 . . . . . . 8 9 . . 5 . . 7 2 . . . . . . 8 . . . .
5 8 6 4 7 9 1 2 3 2 4 9 3 6 1 5 7 8 1 7 3 8 5 2 9 4 6 7 1 8 9 3 5 4 6 2 3 5 2 7 4 6 8 9 1 9 6 4 1 2 8 7 3 5 6 2 7 5 1 4 3 8 9 8 3 5 6 9 7 2 1 4 4 9 1 2 8 3 6 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4223_hard
586479123249361578173852946718935462352746891964128735627514389835697214491283657 #1 Extreme (31346) bf Locked Candidates Type 1 (Pointing): 5 in b9 => r9c4<>5 Locked Candidates Type 1 (Pointing): 7 in b9 => r9c123<>7 Hidden Pair: 5,7 in r9c89 => r9c89<>1, r9c89<>3, r9c89<>4, r9c89<>6 Brute Force: r5c7=8 ...
sudoku_normal_hard_127
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
9.....4.7.7.42.89.4.8..7....4..691.2..6.7.349...1..76.....3.51.5.........2...8..4
912586437675423891438917625847369152156872349293145768789234516564791283321658974
9 . . . . . 4 . 7 . 7 . 4 2 . 8 9 . 4 . 8 . . 7 . . . . 4 . . 6 9 1 . 2 . . 6 . 7 . 3 4 9 . . . 1 . . 7 6 . . . . . 3 . 5 1 . 5 . . . . . . . . . 2 . . . 8 . . 4
9 1 2 5 8 6 4 3 7 6 7 5 4 2 3 8 9 1 4 3 8 9 1 7 6 2 5 8 4 7 3 6 9 1 5 2 1 5 6 8 7 2 3 4 9 2 9 3 1 4 5 7 6 8 7 8 9 2 3 4 5 1 6 5 6 4 7 9 1 2 8 3 3 2 1 6 5 8 9 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8577_hard
912586437675423891438917625847369152156872349293145768789234516564791283321658974 #1 Extreme (28602) bf Locked Candidates Type 1 (Pointing): 9 in b2 => r3c789<>9 Locked Candidates Type 1 (Pointing): 2 in b9 => r8c46<>2 Hidden Pair: 2,4 in r1c3,r3c1 => r1c3,r3c1<>1, r1c3,r3c1<>3, r1c3<>5, r3c1<>6 Brute Force...
sudoku_normal_extremely_hard_127
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
9.......7.7.42.8....8..7....4..69..2..6.7.3.....1...6.....3.51.5.........2...8..4
912586437675423891438917625847369152156872349293145768789234516564791283321658974
9 . . . . . . . 7 . 7 . 4 2 . 8 . . . . 8 . . 7 . . . . 4 . . 6 9 . . 2 . . 6 . 7 . 3 . . . . . 1 . . . 6 . . . . . 3 . 5 1 . 5 . . . . . . . . . 2 . . . 8 . . 4
9 1 2 5 8 6 4 3 7 6 7 5 4 2 3 8 9 1 4 3 8 9 1 7 6 2 5 8 4 7 3 6 9 1 5 2 1 5 6 8 7 2 3 4 9 2 9 3 1 4 5 7 6 8 7 8 9 2 3 4 5 1 6 5 6 4 7 9 1 2 8 3 3 2 1 6 5 8 9 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8577_hard
912586437675423891438917625847369152156872349293145768789234516564791283321658974 #1 Extreme (28602) bf Locked Candidates Type 1 (Pointing): 9 in b2 => r3c789<>9 Locked Candidates Type 1 (Pointing): 2 in b9 => r8c46<>2 Hidden Pair: 2,4 in r1c3,r3c1 => r1c3,r3c1<>1, r1c3,r3c1<>3, r1c3<>5, r3c1<>6 Brute Force...
sudoku_normal_hard_128
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.7.9..6.2..3.6579.9.6.27.8...7.9.8166..7..923.9...6547.6..7.2.97....9.6.4.96...7.
874913652213865794956427381347592816685741923192386547568174239731259468429638175
. 7 . 9 . . 6 . 2 . . 3 . 6 5 7 9 . 9 . 6 . 2 7 . 8 . . . 7 . 9 . 8 1 6 6 . . 7 . . 9 2 3 . 9 . . . 6 5 4 7 . 6 . . 7 . 2 . 9 7 . . . . 9 . 6 . 4 . 9 6 . . . 7 .
8 7 4 9 1 3 6 5 2 2 1 3 8 6 5 7 9 4 9 5 6 4 2 7 3 8 1 3 4 7 5 9 2 8 1 6 6 8 5 7 4 1 9 2 3 1 9 2 3 8 6 5 4 7 5 6 8 1 7 4 2 3 9 7 3 1 2 5 9 4 6 8 4 2 9 6 3 8 1 7 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4702_hard
874913652213865794956427381347592816685741923192386547568174239731259468429638175 #1 Extreme (36012) bf Hidden Single: r3c6=7 Hidden Single: r9c3=9 Hidden Single: r4c9=6 Hidden Single: r8c1=7 Hidden Single: r2c5=6 Hidden Single: r7c2=6 Hidden Single: r6c6=6 Finned Swordfish: 2 r249 c126 fr4c4 =>...
sudoku_normal_extremely_hard_128
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.7.9..6.2..3..5.....6.2..8...7.9..1.6..7......9....5.7....7.2.9.....9.6.4..6.....
874913652213865794956427381347592816685741923192386547568174239731259468429638175
. 7 . 9 . . 6 . 2 . . 3 . . 5 . . . . . 6 . 2 . . 8 . . . 7 . 9 . . 1 . 6 . . 7 . . . . . . 9 . . . . 5 . 7 . . . . 7 . 2 . 9 . . . . . 9 . 6 . 4 . . 6 . . . . .
8 7 4 9 1 3 6 5 2 2 1 3 8 6 5 7 9 4 9 5 6 4 2 7 3 8 1 3 4 7 5 9 2 8 1 6 6 8 5 7 4 1 9 2 3 1 9 2 3 8 6 5 4 7 5 6 8 1 7 4 2 3 9 7 3 1 2 5 9 4 6 8 4 2 9 6 3 8 1 7 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4702_hard
874913652213865794956427381347592816685741923192386547568174239731259468429638175 #1 Extreme (36012) bf Hidden Single: r3c6=7 Hidden Single: r9c3=9 Hidden Single: r4c9=6 Hidden Single: r8c1=7 Hidden Single: r2c5=6 Hidden Single: r7c2=6 Hidden Single: r6c6=6 Finned Swordfish: 2 r249 c126 fr4c4 =>...
sudoku_normal_hard_129
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..5..23..21..7...59..5...2...2.1568.16.7..5.2.59.26.7.52...7..6..7.5..4..9.....5.
745192368216873495938564721372415689164789532859326174523947816687251943491638257
. . 5 . . 2 3 . . 2 1 . . 7 . . . 5 9 . . 5 . . . 2 . . . 2 . 1 5 6 8 . 1 6 . 7 . . 5 . 2 . 5 9 . 2 6 . 7 . 5 2 . . . 7 . . 6 . . 7 . 5 . . 4 . . 9 . . . . . 5 .
7 4 5 1 9 2 3 6 8 2 1 6 8 7 3 4 9 5 9 3 8 5 6 4 7 2 1 3 7 2 4 1 5 6 8 9 1 6 4 7 8 9 5 3 2 8 5 9 3 2 6 1 7 4 5 2 3 9 4 7 8 1 6 6 8 7 2 5 1 9 4 3 4 9 1 6 3 8 2 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3075_hard
745192368216873495938564721372415689164789532859326174523947816687251943491638257 #1 Extreme (23968) bf Hidden Single: r4c3=2 Hidden Single: r4c7=6 Hidden Single: r5c4=7 Empty Rectangle: 5 in b5 (r59c8) => r9c6<>5 Brute Force: r5c7=5 Hidden Single: r1c3=5 Hidden Single: r4c6=5 Hidden Single: r9c...
sudoku_normal_extremely_hard_129
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.....23..21..7...59..5.........1..8.16......2..9.26.7.52...7..6..7....4..9.......
745192368216873495938564721372415689164789532859326174523947816687251943491638257
. . . . . 2 3 . . 2 1 . . 7 . . . 5 9 . . 5 . . . . . . . . . 1 . . 8 . 1 6 . . . . . . 2 . . 9 . 2 6 . 7 . 5 2 . . . 7 . . 6 . . 7 . . . . 4 . . 9 . . . . . . .
7 4 5 1 9 2 3 6 8 2 1 6 8 7 3 4 9 5 9 3 8 5 6 4 7 2 1 3 7 2 4 1 5 6 8 9 1 6 4 7 8 9 5 3 2 8 5 9 3 2 6 1 7 4 5 2 3 9 4 7 8 1 6 6 8 7 2 5 1 9 4 3 4 9 1 6 3 8 2 5 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3075_hard
745192368216873495938564721372415689164789532859326174523947816687251943491638257 #1 Extreme (23968) bf Hidden Single: r4c3=2 Hidden Single: r4c7=6 Hidden Single: r5c4=7 Empty Rectangle: 5 in b5 (r59c8) => r9c6<>5 Brute Force: r5c7=5 Hidden Single: r1c3=5 Hidden Single: r4c6=5 Hidden Single: r9c...
sudoku_normal_hard_130
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.896.2.172.1...9.6....9182...81...726..2.8149412.7968..23........4...2..8..92...1
389652417251487936746391825938146572675238149412579683123865794594713268867924351
. 8 9 6 . 2 . 1 7 2 . 1 . . . 9 . 6 . . . . 9 1 8 2 . . . 8 1 . . . 7 2 6 . . 2 . 8 1 4 9 4 1 2 . 7 9 6 8 . . 2 3 . . . . . . . . 4 . . . 2 . . 8 . . 9 2 . . . 1
3 8 9 6 5 2 4 1 7 2 5 1 4 8 7 9 3 6 7 4 6 3 9 1 8 2 5 9 3 8 1 4 6 5 7 2 6 7 5 2 3 8 1 4 9 4 1 2 5 7 9 6 8 3 1 2 3 8 6 5 7 9 4 5 9 4 7 1 3 2 6 8 8 6 7 9 2 4 3 5 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5088_hard
389652417251487936746391825938146572675238149412579683123865794594713268867924351 #1 Extreme (13472) bf Hidden Single: r5c7=1 Hidden Single: r6c7=6 Hidden Single: r2c1=2 Hidden Single: r4c9=2 Hidden Single: r4c3=8 Hidden Single: r3c5=9 Hidden Single: r9c5=2 Hidden Single: r5c4=2 Hidden Single...
sudoku_normal_extremely_hard_130
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.896.2.17......9.6.....182....1...7.6....8..9.12.79.8..23........4...2..8..9.....
389652417251487936746391825938146572675238149412579683123865794594713268867924351
. 8 9 6 . 2 . 1 7 . . . . . . 9 . 6 . . . . . 1 8 2 . . . . 1 . . . 7 . 6 . . . . 8 . . 9 . 1 2 . 7 9 . 8 . . 2 3 . . . . . . . . 4 . . . 2 . . 8 . . 9 . . . . .
3 8 9 6 5 2 4 1 7 2 5 1 4 8 7 9 3 6 7 4 6 3 9 1 8 2 5 9 3 8 1 4 6 5 7 2 6 7 5 2 3 8 1 4 9 4 1 2 5 7 9 6 8 3 1 2 3 8 6 5 7 9 4 5 9 4 7 1 3 2 6 8 8 6 7 9 2 4 3 5 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5088_hard
389652417251487936746391825938146572675238149412579683123865794594713268867924351 #1 Extreme (13472) bf Hidden Single: r5c7=1 Hidden Single: r6c7=6 Hidden Single: r2c1=2 Hidden Single: r4c9=2 Hidden Single: r4c3=8 Hidden Single: r3c5=9 Hidden Single: r9c5=2 Hidden Single: r5c4=2 Hidden Single...
sudoku_normal_hard_131
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..46..3..6...9..4..2...4..8..6.3...2.4..867..38...9.5...8.1...44..9...1.17...5...
814672395635198247729354168596731482241586739387429651968213574452967813173845926
. . 4 6 . . 3 . . 6 . . . 9 . . 4 . . 2 . . . 4 . . 8 . . 6 . 3 . . . 2 . 4 . . 8 6 7 . . 3 8 . . . 9 . 5 . . . 8 . 1 . . . 4 4 . . 9 . . . 1 . 1 7 . . . 5 . . .
8 1 4 6 7 2 3 9 5 6 3 5 1 9 8 2 4 7 7 2 9 3 5 4 1 6 8 5 9 6 7 3 1 4 8 2 2 4 1 5 8 6 7 3 9 3 8 7 4 2 9 6 5 1 9 6 8 2 1 3 5 7 4 4 5 2 9 6 7 8 1 3 1 7 3 8 4 5 9 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5844_hard
814672395635198247729354168596731482241586739387429651968213574452967813173845926 #1 Extreme (16972) bf Brute Force: r5c5=8 Locked Candidates Type 1 (Pointing): 5 in b5 => r23c4<>5 Finned Swordfish: 8 r168 c267 fr1c1 => r2c2<>8 Locked Candidates Type 1 (Pointing): 8 in b1 => r1c6<>8 Discontinuous Nice Lo...
sudoku_normal_extremely_hard_131
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
...6..3..6...9..4..2...4..8..6.3...2.4....7..3....9.5...8.1...4...9...1.17...5...
814672395635198247729354168596731482241586739387429651968213574452967813173845926
. . . 6 . . 3 . . 6 . . . 9 . . 4 . . 2 . . . 4 . . 8 . . 6 . 3 . . . 2 . 4 . . . . 7 . . 3 . . . . 9 . 5 . . . 8 . 1 . . . 4 . . . 9 . . . 1 . 1 7 . . . 5 . . .
8 1 4 6 7 2 3 9 5 6 3 5 1 9 8 2 4 7 7 2 9 3 5 4 1 6 8 5 9 6 7 3 1 4 8 2 2 4 1 5 8 6 7 3 9 3 8 7 4 2 9 6 5 1 9 6 8 2 1 3 5 7 4 4 5 2 9 6 7 8 1 3 1 7 3 8 4 5 9 2 6
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5844_hard
814672395635198247729354168596731482241586739387429651968213574452967813173845926 #1 Extreme (16972) bf Brute Force: r5c5=8 Locked Candidates Type 1 (Pointing): 5 in b5 => r23c4<>5 Finned Swordfish: 8 r168 c267 fr1c1 => r2c2<>8 Locked Candidates Type 1 (Pointing): 8 in b1 => r1c6<>8 Discontinuous Nice Lo...
sudoku_normal_hard_132
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
6.....8.2.728..46..1.6..57...17...2.23918675476...4....9..3...71..9...8...7.6...5
645379812972815463813642579451793628239186754768524931596238147124957386387461295
6 . . . . . 8 . 2 . 7 2 8 . . 4 6 . . 1 . 6 . . 5 7 . . . 1 7 . . . 2 . 2 3 9 1 8 6 7 5 4 7 6 . . . 4 . . . . 9 . . 3 . . . 7 1 . . 9 . . . 8 . . . 7 . 6 . . . 5
6 4 5 3 7 9 8 1 2 9 7 2 8 1 5 4 6 3 8 1 3 6 4 2 5 7 9 4 5 1 7 9 3 6 2 8 2 3 9 1 8 6 7 5 4 7 6 8 5 2 4 9 3 1 5 9 6 2 3 8 1 4 7 1 2 4 9 5 7 3 8 6 3 8 7 4 6 1 2 9 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7147_hard
645379812972815463813642579451793628239186754768524931596238147124957386387461295 #1 Extreme (22132) bf Brute Force: r5c8=5 Forcing Net Contradiction in c9 => r1c5<>5 r1c5=5 (r1c5<>9) (r1c5<>7 r1c6=7 r1c6<>9) (r4c5<>5 r4c5=9 r4c1<>9) (r2c5<>5) r2c6<>5 r2c1=5 r2c1<>9 r3c1=9 r1c3<>9 r1c8=9 r2c9<>9 r1c5=5 (r4c5<...
sudoku_normal_extremely_hard_132
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
6.....8.2.728...6..1.6..57...17...2.2...8....76...4....9..3....1..9...8.....6...5
645379812972815463813642579451793628239186754768524931596238147124957386387461295
6 . . . . . 8 . 2 . 7 2 8 . . . 6 . . 1 . 6 . . 5 7 . . . 1 7 . . . 2 . 2 . . . 8 . . . . 7 6 . . . 4 . . . . 9 . . 3 . . . . 1 . . 9 . . . 8 . . . . . 6 . . . 5
6 4 5 3 7 9 8 1 2 9 7 2 8 1 5 4 6 3 8 1 3 6 4 2 5 7 9 4 5 1 7 9 3 6 2 8 2 3 9 1 8 6 7 5 4 7 6 8 5 2 4 9 3 1 5 9 6 2 3 8 1 4 7 1 2 4 9 5 7 3 8 6 3 8 7 4 6 1 2 9 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7147_hard
645379812972815463813642579451793628239186754768524931596238147124957386387461295 #1 Extreme (22132) bf Brute Force: r5c8=5 Forcing Net Contradiction in c9 => r1c5<>5 r1c5=5 (r1c5<>9) (r1c5<>7 r1c6=7 r1c6<>9) (r4c5<>5 r4c5=9 r4c1<>9) (r2c5<>5) r2c6<>5 r2c1=5 r2c1<>9 r3c1=9 r1c3<>9 r1c8=9 r2c9<>9 r1c5=5 (r4c5<...
sudoku_normal_hard_133
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
4.8...6.2.25...4..69.4...582.9.4.56..86.5.21454.....89..4.....6..2.31.458....4.2.
438517692125896437697423158279148563386759214541362789914285376762931845853674921
4 . 8 . . . 6 . 2 . 2 5 . . . 4 . . 6 9 . 4 . . . 5 8 2 . 9 . 4 . 5 6 . . 8 6 . 5 . 2 1 4 5 4 . . . . . 8 9 . . 4 . . . . . 6 . . 2 . 3 1 . 4 5 8 . . . . 4 . 2 .
4 3 8 5 1 7 6 9 2 1 2 5 8 9 6 4 3 7 6 9 7 4 2 3 1 5 8 2 7 9 1 4 8 5 6 3 3 8 6 7 5 9 2 1 4 5 4 1 3 6 2 7 8 9 9 1 4 2 8 5 3 7 6 7 6 2 9 3 1 8 4 5 8 5 3 6 7 4 9 2 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4685_hard
438517692125896437697423158279148563386759214541362789914285376762931845853674921 #1 Extreme (14022) bf Hidden Single: r6c1=5 Hidden Single: r4c8=6 Hidden Single: r1c3=8 Hidden Single: r4c5=4 Hidden Single: r1c9=2 Hidden Single: r4c1=2 Hidden Single: r1c1=4 Hidden Single: r7c3=4 Hidden Single...
sudoku_normal_extremely_hard_133
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
......6...25...4..69.4...58..9...5...86.5.2...4.....89........6..2.31..58....4.2.
438517692125896437697423158279148563386759214541362789914285376762931845853674921
. . . . . . 6 . . . 2 5 . . . 4 . . 6 9 . 4 . . . 5 8 . . 9 . . . 5 . . . 8 6 . 5 . 2 . . . 4 . . . . . 8 9 . . . . . . . . 6 . . 2 . 3 1 . . 5 8 . . . . 4 . 2 .
4 3 8 5 1 7 6 9 2 1 2 5 8 9 6 4 3 7 6 9 7 4 2 3 1 5 8 2 7 9 1 4 8 5 6 3 3 8 6 7 5 9 2 1 4 5 4 1 3 6 2 7 8 9 9 1 4 2 8 5 3 7 6 7 6 2 9 3 1 8 4 5 8 5 3 6 7 4 9 2 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4685_hard
438517692125896437697423158279148563386759214541362789914285376762931845853674921 #1 Extreme (14022) bf Hidden Single: r6c1=5 Hidden Single: r4c8=6 Hidden Single: r1c3=8 Hidden Single: r4c5=4 Hidden Single: r1c9=2 Hidden Single: r4c1=2 Hidden Single: r1c1=4 Hidden Single: r7c3=4 Hidden Single...
sudoku_normal_hard_134
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
52...7..387.31.5..9134567..638...9.1...9..3...9213...5367........96.3....8.7..639
526897413874312596913456728638275941451968372792134865367529184149683257285741639
5 2 . . . 7 . . 3 8 7 . 3 1 . 5 . . 9 1 3 4 5 6 7 . . 6 3 8 . . . 9 . 1 . . . 9 . . 3 . . . 9 2 1 3 . . . 5 3 6 7 . . . . . . . . 9 6 . 3 . . . . 8 . 7 . . 6 3 9
5 2 6 8 9 7 4 1 3 8 7 4 3 1 2 5 9 6 9 1 3 4 5 6 7 2 8 6 3 8 2 7 5 9 4 1 4 5 1 9 6 8 3 7 2 7 9 2 1 3 4 8 6 5 3 6 7 5 2 9 1 8 4 1 4 9 6 8 3 2 5 7 2 8 5 7 4 1 6 3 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_578_easy
526897413874312596913456728638275941451968372792134865367529184149683257285741639 #1 Easy (420) Naked Single: r3c3=3 Hidden Single: r3c5=5 Hidden Single: r6c2=9 Hidden Single: r2c1=8 Hidden Single: r8c4=6 Hidden Single: r7c1=3 Hidden Single: r8c3=9 Hidden Single: r1c9=3 Hidden Single: r4c2=3 ...
sudoku_normal_extremely_hard_134
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
5....7......31.5..91.4.67..6.8...9.1...9..3....21....5.67...........3....8.7...39
526897413874312596913456728638275941451968372792134865367529184149683257285741639
5 . . . . 7 . . . . . . 3 1 . 5 . . 9 1 . 4 . 6 7 . . 6 . 8 . . . 9 . 1 . . . 9 . . 3 . . . . 2 1 . . . . 5 . 6 7 . . . . . . . . . . . 3 . . . . 8 . 7 . . . 3 9
5 2 6 8 9 7 4 1 3 8 7 4 3 1 2 5 9 6 9 1 3 4 5 6 7 2 8 6 3 8 2 7 5 9 4 1 4 5 1 9 6 8 3 7 2 7 9 2 1 3 4 8 6 5 3 6 7 5 2 9 1 8 4 1 4 9 6 8 3 2 5 7 2 8 5 7 4 1 6 3 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_578_easy
526897413874312596913456728638275941451968372792134865367529184149683257285741639 #1 Easy (420) Naked Single: r3c3=3 Hidden Single: r3c5=5 Hidden Single: r6c2=9 Hidden Single: r2c1=8 Hidden Single: r8c4=6 Hidden Single: r7c1=3 Hidden Single: r8c3=9 Hidden Single: r1c9=3 Hidden Single: r4c2=3 ...
sudoku_normal_hard_135
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
1293.756.3.4...7987.8..9213983.1.42..4..9..3....8.3.5.......3.....63....832...671
129387564364521798758469213983715426541296837276843159695178342417632985832954671
1 2 9 3 . 7 5 6 . 3 . 4 . . . 7 9 8 7 . 8 . . 9 2 1 3 9 8 3 . 1 . 4 2 . . 4 . . 9 . . 3 . . . . 8 . 3 . 5 . . . . . . . 3 . . . . . 6 3 . . . . 8 3 2 . . . 6 7 1
1 2 9 3 8 7 5 6 4 3 6 4 5 2 1 7 9 8 7 5 8 4 6 9 2 1 3 9 8 3 7 1 5 4 2 6 5 4 1 2 9 6 8 3 7 2 7 6 8 4 3 1 5 9 6 9 5 1 7 8 3 4 2 4 1 7 6 3 2 9 8 5 8 3 2 9 5 4 6 7 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_421_easy
129387564364521798758469213983715426541296837276843159695178342417632985832954671 #1 Easy (354) Hidden Single: r5c8=3 Hidden Single: r4c2=8 Hidden Single: r9c2=3 Hidden Single: r2c1=3 Hidden Single: r3c8=1 Hidden Single: r4c3=3 Hidden Single: r1c4=3 Hidden Single: r9c7=6 Naked Single: r4c7=4 ...
sudoku_normal_extremely_hard_135
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
1.9..75........79.7.8..9..39...1..2..4..9.......8.3.5.......3.....63....8.2....71
129387564364521798758469213983715426541296837276843159695178342417632985832954671
1 . 9 . . 7 5 . . . . . . . . 7 9 . 7 . 8 . . 9 . . 3 9 . . . 1 . . 2 . . 4 . . 9 . . . . . . . 8 . 3 . 5 . . . . . . . 3 . . . . . 6 3 . . . . 8 . 2 . . . . 7 1
1 2 9 3 8 7 5 6 4 3 6 4 5 2 1 7 9 8 7 5 8 4 6 9 2 1 3 9 8 3 7 1 5 4 2 6 5 4 1 2 9 6 8 3 7 2 7 6 8 4 3 1 5 9 6 9 5 1 7 8 3 4 2 4 1 7 6 3 2 9 8 5 8 3 2 9 5 4 6 7 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_421_easy
129387564364521798758469213983715426541296837276843159695178342417632985832954671 #1 Easy (354) Hidden Single: r5c8=3 Hidden Single: r4c2=8 Hidden Single: r9c2=3 Hidden Single: r2c1=3 Hidden Single: r3c8=1 Hidden Single: r4c3=3 Hidden Single: r1c4=3 Hidden Single: r9c7=6 Naked Single: r4c7=4 ...
sudoku_normal_hard_136
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..65..1...2......9....9.24.65.1....8..1.859..78..6.5......43....6......2..86..73.
936524187524718369817396245659137428341285976782469513275843691463971852198652734
. . 6 5 . . 1 . . . 2 . . . . . . 9 . . . . 9 . 2 4 . 6 5 . 1 . . . . 8 . . 1 . 8 5 9 . . 7 8 . . 6 . 5 . . . . . . 4 3 . . . . 6 . . . . . . 2 . . 8 6 . . 7 3 .
9 3 6 5 2 4 1 8 7 5 2 4 7 1 8 3 6 9 8 1 7 3 9 6 2 4 5 6 5 9 1 3 7 4 2 8 3 4 1 2 8 5 9 7 6 7 8 2 4 6 9 5 1 3 2 7 5 8 4 3 6 9 1 4 6 3 9 7 1 8 5 2 1 9 8 6 5 2 7 3 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9709_hard
936524187524718369817396245659137428341285976782469513275843691463971852198652734 #1 Extreme (36400) bf Brute Force: r5c6=5 Brute Force: r5c5=8 Brute Force: r5c7=9 Locked Candidates Type 1 (Pointing): 9 in b4 => r78c3<>9 Empty Rectangle: 3 in b5 (r24c7) => r2c4<>3 Forcing Chain Contradiction in r4 => ...
sudoku_normal_extremely_hard_136
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..65..1...2......9....9.24.65.1....8..1......78..6.5......43....6......2..86..73.
936524187524718369817396245659137428341285976782469513275843691463971852198652734
. . 6 5 . . 1 . . . 2 . . . . . . 9 . . . . 9 . 2 4 . 6 5 . 1 . . . . 8 . . 1 . . . . . . 7 8 . . 6 . 5 . . . . . . 4 3 . . . . 6 . . . . . . 2 . . 8 6 . . 7 3 .
9 3 6 5 2 4 1 8 7 5 2 4 7 1 8 3 6 9 8 1 7 3 9 6 2 4 5 6 5 9 1 3 7 4 2 8 3 4 1 2 8 5 9 7 6 7 8 2 4 6 9 5 1 3 2 7 5 8 4 3 6 9 1 4 6 3 9 7 1 8 5 2 1 9 8 6 5 2 7 3 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_9709_hard
936524187524718369817396245659137428341285976782469513275843691463971852198652734 #1 Extreme (36400) bf Brute Force: r5c6=5 Brute Force: r5c5=8 Brute Force: r5c7=9 Locked Candidates Type 1 (Pointing): 9 in b4 => r78c3<>9 Empty Rectangle: 3 in b5 (r24c7) => r2c4<>3 Forcing Chain Contradiction in r4 => ...
sudoku_normal_hard_137
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.3.4...2.1...9.5....7..2.......8..1.8..2...59..69..8....13...7.7...6.1...4...7..5
935418726162793584487652391293586417874231659516974832651349278729865143348127965
. 3 . 4 . . . 2 . 1 . . . 9 . 5 . . . . 7 . . 2 . . . . . . . 8 . . 1 . 8 . . 2 . . . 5 9 . . 6 9 . . 8 . . . . 1 3 . . . 7 . 7 . . . 6 . 1 . . . 4 . . . 7 . . 5
9 3 5 4 1 8 7 2 6 1 6 2 7 9 3 5 8 4 4 8 7 6 5 2 3 9 1 2 9 3 5 8 6 4 1 7 8 7 4 2 3 1 6 5 9 5 1 6 9 7 4 8 3 2 6 5 1 3 4 9 2 7 8 7 2 9 8 6 5 1 4 3 3 4 8 1 2 7 9 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4848_hard
935418726162793584487652391293586417874231659516974832651349278729865143348127965 #1 Extreme (26792) bf Brute Force: r5c4=2 Finned Swordfish: 2 r268 c239 fr6c1 => r4c23<>2 Forcing Chain Contradiction in r1 => r7c7<>6 r7c7=6 r7c2<>6 r79c1=6 r1c1<>6 r7c7=6 r5c7<>6 r5c6=6 r1c6<>6 r7c7=6 r1c7<>6 r7c7=6 r9c...
sudoku_normal_extremely_hard_137
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.3.4...2.1...9.5....7..2.......8..1.8......59..69..8....13...7.7...6.1...4...7..5
935418726162793584487652391293586417874231659516974832651349278729865143348127965
. 3 . 4 . . . 2 . 1 . . . 9 . 5 . . . . 7 . . 2 . . . . . . . 8 . . 1 . 8 . . . . . . 5 9 . . 6 9 . . 8 . . . . 1 3 . . . 7 . 7 . . . 6 . 1 . . . 4 . . . 7 . . 5
9 3 5 4 1 8 7 2 6 1 6 2 7 9 3 5 8 4 4 8 7 6 5 2 3 9 1 2 9 3 5 8 6 4 1 7 8 7 4 2 3 1 6 5 9 5 1 6 9 7 4 8 3 2 6 5 1 3 4 9 2 7 8 7 2 9 8 6 5 1 4 3 3 4 8 1 2 7 9 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4848_hard
935418726162793584487652391293586417874231659516974832651349278729865143348127965 #1 Extreme (26792) bf Brute Force: r5c4=2 Finned Swordfish: 2 r268 c239 fr6c1 => r4c23<>2 Forcing Chain Contradiction in r1 => r7c7<>6 r7c7=6 r7c2<>6 r79c1=6 r1c1<>6 r7c7=6 r5c7<>6 r5c6=6 r1c6<>6 r7c7=6 r1c7<>6 r7c7=6 r9c...
sudoku_normal_hard_138
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
9....471..719....3.5.........32..4..7...4923..2.....5.6..79.....8.46.9.......8...
968354712271986543354172896893215467715649238426837159642791385587463921139528674
9 . . . . 4 7 1 . . 7 1 9 . . . . 3 . 5 . . . . . . . . . 3 2 . . 4 . . 7 . . . 4 9 2 3 . . 2 . . . . . 5 . 6 . . 7 9 . . . . . 8 . 4 6 . 9 . . . . . . . 8 . . .
9 6 8 3 5 4 7 1 2 2 7 1 9 8 6 5 4 3 3 5 4 1 7 2 8 9 6 8 9 3 2 1 5 4 6 7 7 1 5 6 4 9 2 3 8 4 2 6 8 3 7 1 5 9 6 4 2 7 9 1 3 8 5 5 8 7 4 6 3 9 2 1 1 3 9 5 2 8 6 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3325_hard
968354712271986543354172896893215467715649238426837159642791385587463921139528674 #1 Extreme (34122) bf Brute Force: r5c8=3 Brute Force: r5c5=4 Locked Candidates Type 2 (Claiming): 4 in c2 => r79c3,r9c1<>4 XYZ-Wing: 2/5/7 in r78c3,r8c8 => r8c1<>2 Discontinuous Nice Loop: 2 r2c8 -2- r8c8 -7- r8c3 =7= r9c3...
sudoku_normal_extremely_hard_138
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
9....471..719....3.5.........32..4..7....92...2.....5.6..79.....8.46.9.......8...
968354712271986543354172896893215467715649238426837159642791385587463921139528674
9 . . . . 4 7 1 . . 7 1 9 . . . . 3 . 5 . . . . . . . . . 3 2 . . 4 . . 7 . . . . 9 2 . . . 2 . . . . . 5 . 6 . . 7 9 . . . . . 8 . 4 6 . 9 . . . . . . . 8 . . .
9 6 8 3 5 4 7 1 2 2 7 1 9 8 6 5 4 3 3 5 4 1 7 2 8 9 6 8 9 3 2 1 5 4 6 7 7 1 5 6 4 9 2 3 8 4 2 6 8 3 7 1 5 9 6 4 2 7 9 1 3 8 5 5 8 7 4 6 3 9 2 1 1 3 9 5 2 8 6 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_3325_hard
968354712271986543354172896893215467715649238426837159642791385587463921139528674 #1 Extreme (34122) bf Brute Force: r5c8=3 Brute Force: r5c5=4 Locked Candidates Type 2 (Claiming): 4 in c2 => r79c3,r9c1<>4 XYZ-Wing: 2/5/7 in r78c3,r8c8 => r8c1<>2 Discontinuous Nice Loop: 2 r2c8 -2- r8c8 -7- r8c3 =7= r9c3...
sudoku_normal_hard_139
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2..4..6.5..73.4.......8..7...9.4.8.4..87.3.9819..3.....5.6....6..4.7..5.7.3..6..
728549163596731428143628957367914582452876319819253746935162874681497235274385691
. 2 . . 4 . . 6 . 5 . . 7 3 . 4 . . . . . . . 8 . . 7 . . . 9 . 4 . 8 . 4 . . 8 7 . 3 . 9 8 1 9 . . 3 . . . . . 5 . 6 . . . . 6 . . 4 . 7 . . 5 . 7 . 3 . . 6 . .
7 2 8 5 4 9 1 6 3 5 9 6 7 3 1 4 2 8 1 4 3 6 2 8 9 5 7 3 6 7 9 1 4 5 8 2 4 5 2 8 7 6 3 1 9 8 1 9 2 5 3 7 4 6 9 3 5 1 6 2 8 7 4 6 8 1 4 9 7 2 3 5 2 7 4 3 8 5 6 9 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_6848_hard
728549163596731428143628957367914582452876319819253746935162874681497235274385691 #1 Extreme (22024) bf Hidden Pair: 3,4 in r46c6 => r4c6<>1, r46c6<>2, r46c6<>5, r46c6<>6 Brute Force: r5c4=8 Hidden Single: r6c1=8 Hidden Single: r6c6=3 Naked Single: r4c6=4 Locked Candidates Type 1 (Pointing): 7 in b4 =...
sudoku_normal_extremely_hard_139
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2..4..6.5..73.4.......8..7...9...8.4...7.3.9.19........5.6....6..4.7..5.7.3..6..
728549163596731428143628957367914582452876319819253746935162874681497235274385691
. 2 . . 4 . . 6 . 5 . . 7 3 . 4 . . . . . . . 8 . . 7 . . . 9 . . . 8 . 4 . . . 7 . 3 . 9 . 1 9 . . . . . . . . 5 . 6 . . . . 6 . . 4 . 7 . . 5 . 7 . 3 . . 6 . .
7 2 8 5 4 9 1 6 3 5 9 6 7 3 1 4 2 8 1 4 3 6 2 8 9 5 7 3 6 7 9 1 4 5 8 2 4 5 2 8 7 6 3 1 9 8 1 9 2 5 3 7 4 6 9 3 5 1 6 2 8 7 4 6 8 1 4 9 7 2 3 5 2 7 4 3 8 5 6 9 1
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_6848_hard
728549163596731428143628957367914582452876319819253746935162874681497235274385691 #1 Extreme (22024) bf Hidden Pair: 3,4 in r46c6 => r4c6<>1, r46c6<>2, r46c6<>5, r46c6<>6 Brute Force: r5c4=8 Hidden Single: r6c1=8 Hidden Single: r6c6=3 Naked Single: r4c6=4 Locked Candidates Type 1 (Pointing): 7 in b4 =...
sudoku_normal_hard_140
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8....6.9..38...7.....58..2.4539..6.19467.2.3..128..96.........23.9.6...97.....2
158972463946381257732645891274539186819467325365128749681253974523794618497816532
. . 8 . . . . 6 . 9 . . 3 8 . . . 7 . . . . . 5 8 . . 2 . 4 5 3 9 . . 6 . 1 9 4 6 7 . 2 . 3 . . 1 2 8 . . 9 6 . . . . . . . . . 2 3 . 9 . 6 . . . 9 7 . . . . . 2
1 5 8 9 7 2 4 6 3 9 4 6 3 8 1 2 5 7 7 3 2 6 4 5 8 9 1 2 7 4 5 3 9 1 8 6 8 1 9 4 6 7 3 2 5 3 6 5 1 2 8 7 4 9 6 8 1 2 5 3 9 7 4 5 2 3 7 9 4 6 1 8 4 9 7 8 1 6 5 3 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7032_hard
158972463946381257732645891274539186819467325365128749681253974523794618497816532 #1 Extreme (33160) bf Brute Force: r5c5=6 Hidden Single: r4c4=5 Locked Candidates Type 1 (Pointing): 7 in b5 => r178c6<>7 Locked Candidates Type 1 (Pointing): 8 in b5 => r789c6<>8 Locked Candidates Type 1 (Pointing): 9 in b...
sudoku_normal_extremely_hard_140
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8....6.9..38...7.....58..2...3...6.1.4...2.3..12...96.........23.9.6...97.....2
158972463946381257732645891274539186819467325365128749681253974523794618497816532
. . 8 . . . . 6 . 9 . . 3 8 . . . 7 . . . . . 5 8 . . 2 . . . 3 . . . 6 . 1 . 4 . . . 2 . 3 . . 1 2 . . . 9 6 . . . . . . . . . 2 3 . 9 . 6 . . . 9 7 . . . . . 2
1 5 8 9 7 2 4 6 3 9 4 6 3 8 1 2 5 7 7 3 2 6 4 5 8 9 1 2 7 4 5 3 9 1 8 6 8 1 9 4 6 7 3 2 5 3 6 5 1 2 8 7 4 9 6 8 1 2 5 3 9 7 4 5 2 3 7 9 4 6 1 8 4 9 7 8 1 6 5 3 2
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7032_hard
158972463946381257732645891274539186819467325365128749681253974523794618497816532 #1 Extreme (33160) bf Brute Force: r5c5=6 Hidden Single: r4c4=5 Locked Candidates Type 1 (Pointing): 7 in b5 => r178c6<>7 Locked Candidates Type 1 (Pointing): 8 in b5 => r789c6<>8 Locked Candidates Type 1 (Pointing): 9 in b...
sudoku_normal_hard_141
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7..2..6....8.36.......7..5..7...2.45..97.5..12...4.7..31.4....9.8.......6....34..
745281693928536174163974258876312945439765821251849736317428569584697312692153487
7 . . 2 . . 6 . . . . 8 . 3 6 . . . . . . . 7 . . 5 . . 7 . . . 2 . 4 5 . . 9 7 . 5 . . 1 2 . . . 4 . 7 . . 3 1 . 4 . . . . 9 . 8 . . . . . . . 6 . . . . 3 4 . .
7 4 5 2 8 1 6 9 3 9 2 8 5 3 6 1 7 4 1 6 3 9 7 4 2 5 8 8 7 6 3 1 2 9 4 5 4 3 9 7 6 5 8 2 1 2 5 1 8 4 9 7 3 6 3 1 7 4 2 8 5 6 9 5 8 4 6 9 7 3 1 2 6 9 2 1 5 3 4 8 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4076_hard
745281693928536174163974258876312945439765821251849736317428569584697312692153487 #1 Extreme (22156) bf Brute Force: r5c6=5 Hidden Single: r5c4=7 Turbot Fish: 5 r1c5 =5= r2c4 -5- r2c1 =5= r8c1 => r8c5<>5 Finned Swordfish: 5 r169 c235 fr9c4 => r7c5<>5 Forcing Chain Contradiction in r4 => r4c4<>8 r4c4=8 ...
sudoku_normal_extremely_hard_141
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
7..2..6....8.36.......7..5..7...2.45..9.....12...4.7..31.4....9.8.......6....34..
745281693928536174163974258876312945439765821251849736317428569584697312692153487
7 . . 2 . . 6 . . . . 8 . 3 6 . . . . . . . 7 . . 5 . . 7 . . . 2 . 4 5 . . 9 . . . . . 1 2 . . . 4 . 7 . . 3 1 . 4 . . . . 9 . 8 . . . . . . . 6 . . . . 3 4 . .
7 4 5 2 8 1 6 9 3 9 2 8 5 3 6 1 7 4 1 6 3 9 7 4 2 5 8 8 7 6 3 1 2 9 4 5 4 3 9 7 6 5 8 2 1 2 5 1 8 4 9 7 3 6 3 1 7 4 2 8 5 6 9 5 8 4 6 9 7 3 1 2 6 9 2 1 5 3 4 8 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4076_hard
745281693928536174163974258876312945439765821251849736317428569584697312692153487 #1 Extreme (22156) bf Brute Force: r5c6=5 Hidden Single: r5c4=7 Turbot Fish: 5 r1c5 =5= r2c4 -5- r2c1 =5= r8c1 => r8c5<>5 Finned Swordfish: 5 r169 c235 fr9c4 => r7c5<>5 Forcing Chain Contradiction in r4 => r4c4<>8 r4c4=8 ...
sudoku_normal_hard_142
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2.1...6.7.4.6..2....2..7...6..1.4..3718456924.56.2......4.1.36.....8.49.4..261..
928174365714563928653289714862917453371845692495632871287491536136758249549326187
. 2 . 1 . . . 6 . 7 . 4 . 6 . . 2 . . . . 2 . . 7 . . . 6 . . 1 . 4 . . 3 7 1 8 4 5 6 9 2 4 . 5 6 . 2 . . . . . . 4 . 1 . 3 6 . . . . . 8 . 4 9 . 4 . . 2 6 1 . .
9 2 8 1 7 4 3 6 5 7 1 4 5 6 3 9 2 8 6 5 3 2 8 9 7 1 4 8 6 2 9 1 7 4 5 3 3 7 1 8 4 5 6 9 2 4 9 5 6 3 2 8 7 1 2 8 7 4 9 1 5 3 6 1 3 6 7 5 8 2 4 9 5 4 9 3 2 6 1 8 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7371_hard
928174365714563928653289714862917453371845692495632871287491536136758249549326187 #1 Extreme (25816) bf Hidden Single: r6c1=4 Hidden Single: r8c8=4 Hidden Single: r7c6=1 Turbot Fish: 1 r2c9 =1= r2c2 -1- r6c2 =1= r5c3 => r5c9<>1 Brute Force: r5c8=9 Hidden Single: r5c3=1 Locked Candidates Type 1 (Poi...
sudoku_normal_extremely_hard_142
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
.2.1...6.7.4.6..2....2..7...6..1.4..37..4.6....5.........4...3......8..9.4..2.1..
928174365714563928653289714862917453371845692495632871287491536136758249549326187
. 2 . 1 . . . 6 . 7 . 4 . 6 . . 2 . . . . 2 . . 7 . . . 6 . . 1 . 4 . . 3 7 . . 4 . 6 . . . . 5 . . . . . . . . . 4 . . . 3 . . . . . . 8 . . 9 . 4 . . 2 . 1 . .
9 2 8 1 7 4 3 6 5 7 1 4 5 6 3 9 2 8 6 5 3 2 8 9 7 1 4 8 6 2 9 1 7 4 5 3 3 7 1 8 4 5 6 9 2 4 9 5 6 3 2 8 7 1 2 8 7 4 9 1 5 3 6 1 3 6 7 5 8 2 4 9 5 4 9 3 2 6 1 8 7
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_7371_hard
928174365714563928653289714862917453371845692495632871287491536136758249549326187 #1 Extreme (25816) bf Hidden Single: r6c1=4 Hidden Single: r8c8=4 Hidden Single: r7c6=1 Turbot Fish: 1 r2c9 =1= r2c2 -1- r6c2 =1= r5c3 => r5c9<>1 Brute Force: r5c8=9 Hidden Single: r5c3=1 Locked Candidates Type 1 (Poi...
sudoku_normal_hard_143
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
1...8......9..76..65.2.....8..1.....32.458.....4..6..37......19.....43.8..3...7..
147689532239547681658231974875193246326458197914726853782365419561974328493812765
1 . . . 8 . . . . . . 9 . . 7 6 . . 6 5 . 2 . . . . . 8 . . 1 . . . . . 3 2 . 4 5 8 . . . . . 4 . . 6 . . 3 7 . . . . . . 1 9 . . . . . 4 3 . 8 . . 3 . . . 7 . .
1 4 7 6 8 9 5 3 2 2 3 9 5 4 7 6 8 1 6 5 8 2 3 1 9 7 4 8 7 5 1 9 3 2 4 6 3 2 6 4 5 8 1 9 7 9 1 4 7 2 6 8 5 3 7 8 2 3 6 5 4 1 9 5 6 1 9 7 4 3 2 8 4 9 3 8 1 2 7 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5980_hard
147689532239547681658231974875193246326458197914726853782365419561974328493812765 #1 Extreme (31762) bf Brute Force: r5c4=4 Finned X-Wing: 4 r17 c27 fr1c8 fr1c9 => r3c7<>4 Forcing Chain Contradiction in c1 => r8c4<>6 r8c4=6 r1c4<>6 r3c5=6 r3c1<>6 r8c4=6 r8c4<>7 r6c4=7 r6c4<>8 r5c6=8 r5c6<>3 r5c1=3 r5c1<>6 ...
sudoku_normal_extremely_hard_143
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
1...8......9..76...5.2.....8..1......2..5......4..6..37......19.....43.8..3...7..
147689532239547681658231974875193246326458197914726853782365419561974328493812765
1 . . . 8 . . . . . . 9 . . 7 6 . . . 5 . 2 . . . . . 8 . . 1 . . . . . . 2 . . 5 . . . . . . 4 . . 6 . . 3 7 . . . . . . 1 9 . . . . . 4 3 . 8 . . 3 . . . 7 . .
1 4 7 6 8 9 5 3 2 2 3 9 5 4 7 6 8 1 6 5 8 2 3 1 9 7 4 8 7 5 1 9 3 2 4 6 3 2 6 4 5 8 1 9 7 9 1 4 7 2 6 8 5 3 7 8 2 3 6 5 4 1 9 5 6 1 9 7 4 3 2 8 4 9 3 8 1 2 7 6 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5980_hard
147689532239547681658231974875193246326458197914726853782365419561974328493812765 #1 Extreme (31762) bf Brute Force: r5c4=4 Finned X-Wing: 4 r17 c27 fr1c8 fr1c9 => r3c7<>4 Forcing Chain Contradiction in c1 => r8c4<>6 r8c4=6 r1c4<>6 r3c5=6 r3c1<>6 r8c4=6 r8c4<>7 r6c4=7 r6c4<>8 r5c6=8 r5c6<>3 r5c1=3 r5c1<>6 ...
sudoku_normal_hard_144
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
2.8.6...419.8.4..2.....2.8.78.24.5.6...35847..4.7.6.28...42...7..7.8.24....6.7..5
278963154195874632436512789783241596962358471541796328319425867657189243824637915
2 . 8 . 6 . . . 4 1 9 . 8 . 4 . . 2 . . . . . 2 . 8 . 7 8 . 2 4 . 5 . 6 . . . 3 5 8 4 7 . . 4 . 7 . 6 . 2 8 . . . 4 2 . . . 7 . . 7 . 8 . 2 4 . . . . 6 . 7 . . 5
2 7 8 9 6 3 1 5 4 1 9 5 8 7 4 6 3 2 4 3 6 5 1 2 7 8 9 7 8 3 2 4 1 5 9 6 9 6 2 3 5 8 4 7 1 5 4 1 7 9 6 3 2 8 3 1 9 4 2 5 8 6 7 6 5 7 1 8 9 2 4 3 8 2 4 6 3 7 9 1 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4137_hard
278963154195874632436512789783241596962358471541796328319425867657189243824637915 #1 Extreme (15614) bf Hidden Single: r1c3=8 Hidden Single: r3c6=2 Hidden Single: r5c6=8 Hidden Single: r2c9=2 Hidden Single: r4c5=4 Hidden Single: r5c7=4 Hidden Single: r6c9=8 Hidden Single: r7c4=4 Hidden Single...
sudoku_normal_extremely_hard_144
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
2...6...419.8.4..........8.78.2..5.6....5.....4.7.6.2.....2...7..7.8.24....6.7..5
278963154195874632436512789783241596962358471541796328319425867657189243824637915
2 . . . 6 . . . 4 1 9 . 8 . 4 . . . . . . . . . . 8 . 7 8 . 2 . . 5 . 6 . . . . 5 . . . . . 4 . 7 . 6 . 2 . . . . . 2 . . . 7 . . 7 . 8 . 2 4 . . . . 6 . 7 . . 5
2 7 8 9 6 3 1 5 4 1 9 5 8 7 4 6 3 2 4 3 6 5 1 2 7 8 9 7 8 3 2 4 1 5 9 6 9 6 2 3 5 8 4 7 1 5 4 1 7 9 6 3 2 8 3 1 9 4 2 5 8 6 7 6 5 7 1 8 9 2 4 3 8 2 4 6 3 7 9 1 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4137_hard
278963154195874632436512789783241596962358471541796328319425867657189243824637915 #1 Extreme (15614) bf Hidden Single: r1c3=8 Hidden Single: r3c6=2 Hidden Single: r5c6=8 Hidden Single: r2c9=2 Hidden Single: r4c5=4 Hidden Single: r5c7=4 Hidden Single: r6c9=8 Hidden Single: r7c4=4 Hidden Single...
sudoku_normal_hard_145
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8..6..32..35......5.4..1....2..7.1.6.4198.55.1.7..4.1...9...7..9...1.4.5.....9.
948126573216357489375948612894265731763419825521873946182594367639782154457631298
. . 8 . . 6 . . 3 2 . . 3 5 . . . . . . 5 . 4 . . 1 . . . . 2 . . 7 . 1 . 6 . 4 1 9 8 . 5 5 . 1 . 7 . . 4 . 1 . . . 9 . . . 7 . . 9 . . . 1 . 4 . 5 . . . . . 9 .
9 4 8 1 2 6 5 7 3 2 1 6 3 5 7 4 8 9 3 7 5 9 4 8 6 1 2 8 9 4 2 6 5 7 3 1 7 6 3 4 1 9 8 2 5 5 2 1 8 7 3 9 4 6 1 8 2 5 9 4 3 6 7 6 3 9 7 8 2 1 5 4 4 5 7 6 3 1 2 9 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4365_hard
948126573216357489375948612894265731763419825521873946182594367639782154457631298 #1 Extreme (38294) bf Brute Force: r5c5=1 Hidden Single: r4c9=1 Forcing Net Contradiction in c8 => r7c6<>5 r7c6=5 (r8c6<>5 r8c8=5 r1c8<>5) (r4c6<>5) r5c6<>5 r4c5=5 r1c5<>5 r1c5=2 r1c8<>2 r1c8=7 r7c6=5 (r8c6<>5 r8c8=5 r2c8<>5)...
sudoku_normal_extremely_hard_145
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
..8..6..32..3.......5.4..1....2..7...6.4..8..5.1.7..4.1...9...7..9...1.4.5.....9.
948126573216357489375948612894265731763419825521873946182594367639782154457631298
. . 8 . . 6 . . 3 2 . . 3 . . . . . . . 5 . 4 . . 1 . . . . 2 . . 7 . . . 6 . 4 . . 8 . . 5 . 1 . 7 . . 4 . 1 . . . 9 . . . 7 . . 9 . . . 1 . 4 . 5 . . . . . 9 .
9 4 8 1 2 6 5 7 3 2 1 6 3 5 7 4 8 9 3 7 5 9 4 8 6 1 2 8 9 4 2 6 5 7 3 1 7 6 3 4 1 9 8 2 5 5 2 1 8 7 3 9 4 6 1 8 2 5 9 4 3 6 7 6 3 9 7 8 2 1 5 4 4 5 7 6 3 1 2 9 8
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4365_hard
948126573216357489375948612894265731763419825521873946182594367639782154457631298 #1 Extreme (38294) bf Brute Force: r5c5=1 Hidden Single: r4c9=1 Forcing Net Contradiction in c8 => r7c6<>5 r7c6=5 (r8c6<>5 r8c8=5 r1c8<>5) (r4c6<>5) r5c6<>5 r4c5=5 r1c5<>5 r1c5=2 r1c8<>2 r1c8=7 r7c6=5 (r8c6<>5 r8c8=5 r2c8<>5)...
sudoku_normal_hard_146
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
4.62..8.7..8.......3..8..6......6...641.5....9..7..4.6..4.7.1.9.791....21...29...
496235817518697243732481965387946521641352798925718436264573189879164352153829674
4 . 6 2 . . 8 . 7 . . 8 . . . . . . . 3 . . 8 . . 6 . . . . . . 6 . . . 6 4 1 . 5 . . . . 9 . . 7 . . 4 . 6 . . 4 . 7 . 1 . 9 . 7 9 1 . . . . 2 1 . . . 2 9 . . .
4 9 6 2 3 5 8 1 7 5 1 8 6 9 7 2 4 3 7 3 2 4 8 1 9 6 5 3 8 7 9 4 6 5 2 1 6 4 1 3 5 2 7 9 8 9 2 5 7 1 8 4 3 6 2 6 4 5 7 3 1 8 9 8 7 9 1 6 4 3 5 2 1 5 3 8 2 9 6 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4177_hard
496235817518697243732481965387946521641352798925718436264573189879164352153829674 #1 Extreme (42218) bf Hidden Single: r8c3=9 Empty Rectangle: 9 in b5 (r3c47) => r4c7<>9 Brute Force: r5c2=4 Brute Force: r5c1=6 Brute Force: r5c3=1 Locked Candidates Type 1 (Pointing): 7 in b4 => r4c78<>7 Naked Triple...
sudoku_normal_extremely_hard_146
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
4..2..8.7..8.......3..8..6......6.......5....9..7..4.6..4.7.1.9.7.1....21...29...
496235817518697243732481965387946521641352798925718436264573189879164352153829674
4 . . 2 . . 8 . 7 . . 8 . . . . . . . 3 . . 8 . . 6 . . . . . . 6 . . . . . . . 5 . . . . 9 . . 7 . . 4 . 6 . . 4 . 7 . 1 . 9 . 7 . 1 . . . . 2 1 . . . 2 9 . . .
4 9 6 2 3 5 8 1 7 5 1 8 6 9 7 2 4 3 7 3 2 4 8 1 9 6 5 3 8 7 9 4 6 5 2 1 6 4 1 3 5 2 7 9 8 9 2 5 7 1 8 4 3 6 2 6 4 5 7 3 1 8 9 8 7 9 1 6 4 3 5 2 1 5 3 8 2 9 6 7 4
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4177_hard
496235817518697243732481965387946521641352798925718436264573189879164352153829674 #1 Extreme (42218) bf Hidden Single: r8c3=9 Empty Rectangle: 9 in b5 (r3c47) => r4c7<>9 Brute Force: r5c2=4 Brute Force: r5c1=6 Brute Force: r5c3=1 Locked Candidates Type 1 (Pointing): 7 in b4 => r4c78<>7 Naked Triple...
sudoku_normal_hard_147
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
....4..1....9.27.....6.......6..3.....276.9..8......5..1..5...3..3..92..4......8.
978345612651982734324671598146593827532768941897124356219856473783419265465237189
. . . . 4 . . 1 . . . . 9 . 2 7 . . . . . 6 . . . . . . . 6 . . 3 . . . . . 2 7 6 . 9 . . 8 . . . . . . 5 . . 1 . . 5 . . . 3 . . 3 . . 9 2 . . 4 . . . . . . 8 .
9 7 8 3 4 5 6 1 2 6 5 1 9 8 2 7 3 4 3 2 4 6 7 1 5 9 8 1 4 6 5 9 3 8 2 7 5 3 2 7 6 8 9 4 1 8 9 7 1 2 4 3 5 6 2 1 9 8 5 6 4 7 3 7 8 3 4 1 9 2 6 5 4 6 5 2 3 7 1 8 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8325_hard
978345612651982734324671598146593827532768941897124356219856473783419265465237189 #1 Extreme (34946) bf Grouped Discontinuous Nice Loop: 5 r1c1 -5- r2c123 =5= r2c9 -5- r8c9 =5= r8c12 -5- r9c3 =5= r123c3 -5- r1c1 => r1c1<>5 Grouped Discontinuous Nice Loop: 5 r1c2 -5- r2c123 =5= r2c9 -5- r8c9 =5= r8c12 -5- r9c3 =5=...
sudoku_normal_extremely_hard_147
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
....4..1....9.27.....6.......6..3.....27..9..8......5..1..5...3..3..92..4......8.
978345612651982734324671598146593827532768941897124356219856473783419265465237189
. . . . 4 . . 1 . . . . 9 . 2 7 . . . . . 6 . . . . . . . 6 . . 3 . . . . . 2 7 . . 9 . . 8 . . . . . . 5 . . 1 . . 5 . . . 3 . . 3 . . 9 2 . . 4 . . . . . . 8 .
9 7 8 3 4 5 6 1 2 6 5 1 9 8 2 7 3 4 3 2 4 6 7 1 5 9 8 1 4 6 5 9 3 8 2 7 5 3 2 7 6 8 9 4 1 8 9 7 1 2 4 3 5 6 2 1 9 8 5 6 4 7 3 7 8 3 4 1 9 2 6 5 4 6 5 2 3 7 1 8 9
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_8325_hard
978345612651982734324671598146593827532768941897124356219856473783419265465237189 #1 Extreme (34946) bf Grouped Discontinuous Nice Loop: 5 r1c1 -5- r2c123 =5= r2c9 -5- r8c9 =5= r8c12 -5- r9c3 =5= r123c3 -5- r1c1 => r1c1<>5 Grouped Discontinuous Nice Loop: 5 r1c2 -5- r2c123 =5= r2c9 -5- r8c9 =5= r8c12 -5- r9c3 =5=...
sudoku_normal_hard_148
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
6.472......54.6...7..39..4697.65...4.5293476.4.6.7295..6.5..4...49.6713...7.4.6..
694725813315486279728391546971658324852934761436172958263519487549867132187243695
6 . 4 7 2 . . . . . . 5 4 . 6 . . . 7 . . 3 9 . . 4 6 9 7 . 6 5 . . . 4 . 5 2 9 3 4 7 6 . 4 . 6 . 7 2 9 5 . . 6 . 5 . . 4 . . . 4 9 . 6 7 1 3 . . . 7 . 4 . 6 . .
6 9 4 7 2 5 8 1 3 3 1 5 4 8 6 2 7 9 7 2 8 3 9 1 5 4 6 9 7 1 6 5 8 3 2 4 8 5 2 9 3 4 7 6 1 4 3 6 1 7 2 9 5 8 2 6 3 5 1 9 4 8 7 5 4 9 8 6 7 1 3 2 1 8 7 2 4 3 6 9 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5112_hard
694725813315486279728391546971658324852934761436172958263519487549867132187243695 #1 Extreme (27098) bf Hidden Single: r6c3=6 Hidden Single: r4c5=5 Hidden Single: r1c3=4 Hidden Single: r8c5=6 Hidden Single: r4c2=7 Hidden Single: r2c4=4 Hidden Single: r4c1=9 Hidden Single: r4c9=4 Hidden Single...
sudoku_normal_extremely_hard_148
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
6..72......5..6...7...9..46...6......529.4.......7295..6.5..4...49...13...7.4....
694725813315486279728391546971658324852934761436172958263519487549867132187243695
6 . . 7 2 . . . . . . 5 . . 6 . . . 7 . . . 9 . . 4 6 . . . 6 . . . . . . 5 2 9 . 4 . . . . . . . 7 2 9 5 . . 6 . 5 . . 4 . . . 4 9 . . . 1 3 . . . 7 . 4 . . . .
6 9 4 7 2 5 8 1 3 3 1 5 4 8 6 2 7 9 7 2 8 3 9 1 5 4 6 9 7 1 6 5 8 3 2 4 8 5 2 9 3 4 7 6 1 4 3 6 1 7 2 9 5 8 2 6 3 5 1 9 4 8 7 5 4 9 8 6 7 1 3 2 1 8 7 2 4 3 6 9 5
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_5112_hard
694725813315486279728391546971658324852934761436172958263519487549867132187243695 #1 Extreme (27098) bf Hidden Single: r6c3=6 Hidden Single: r4c5=5 Hidden Single: r1c3=4 Hidden Single: r8c5=6 Hidden Single: r4c2=7 Hidden Single: r2c4=4 Hidden Single: r4c1=9 Hidden Single: r4c9=4 Hidden Single...
sudoku_normal_hard_149
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
...74.19.4...182.7.7.2.9.485........3.71.28...2...4..99.4.27.81...48.97.78.9.1...
832745196495618237671239548549863712367192854128574369954327681213486975786951423
. . . 7 4 . 1 9 . 4 . . . 1 8 2 . 7 . 7 . 2 . 9 . 4 8 5 . . . . . . . . 3 . 7 1 . 2 8 . . . 2 . . . 4 . . 9 9 . 4 . 2 7 . 8 1 . . . 4 8 . 9 7 . 7 8 . 9 . 1 . . .
8 3 2 7 4 5 1 9 6 4 9 5 6 1 8 2 3 7 6 7 1 2 3 9 5 4 8 5 4 9 8 6 3 7 1 2 3 6 7 1 9 2 8 5 4 1 2 8 5 7 4 3 6 9 9 5 4 3 2 7 6 8 1 2 1 3 4 8 6 9 7 5 7 8 6 9 5 1 4 2 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4078_hard
832745196495618237671239548549863712367192854128574369954327681213486975786951423 #1 Extreme (42008) bf Hidden Single: r2c9=7 Hidden Single: r9c1=7 Hidden Single: r7c8=8 Hidden Single: r8c7=9 Locked Candidates Type 1 (Pointing): 4 in b4 => r12c2<>4 Locked Candidates Type 2 (Claiming): 2 in r7 => r8c56...
sudoku_normal_extremely_hard_149
9
9
Each row, column, and 3×3 subgrid must contain all digits from 1 to 9 exactly once. Digits cannot be repeated within any row, column, or 3×3 subgrid.
None
...7..19.....182...7.2.9.485........3.7...8...2...4..99.4.....1.......7..8.9.1...
832745196495618237671239548549863712367192854128574369954327681213486975786951423
. . . 7 . . 1 9 . . . . . 1 8 2 . . . 7 . 2 . 9 . 4 8 5 . . . . . . . . 3 . 7 . . . 8 . . . 2 . . . 4 . . 9 9 . 4 . . . . . 1 . . . . . . . 7 . . 8 . 9 . 1 . . .
8 3 2 7 4 5 1 9 6 4 9 5 6 1 8 2 3 7 6 7 1 2 3 9 5 4 8 5 4 9 8 6 3 7 1 2 3 6 7 1 9 2 8 5 4 1 2 8 5 7 4 3 6 9 9 5 4 3 2 7 6 8 1 2 1 3 4 8 6 9 7 5 7 8 6 9 5 1 4 2 3
Complete the sudoku board based on the rules and visual elements.
9x9_sudoku_4078_hard
832745196495618237671239548549863712367192854128574369954327681213486975786951423 #1 Extreme (42008) bf Hidden Single: r2c9=7 Hidden Single: r9c1=7 Hidden Single: r7c8=8 Hidden Single: r8c7=9 Locked Candidates Type 1 (Pointing): 4 in b4 => r12c2<>4 Locked Candidates Type 2 (Claiming): 2 in r7 => r8c56...