license: apache-2.0
language:
- de
pipeline_tag: text-generation
library_name: transformers
tags:
- instruction-tuned
- german
base_model:
- Boldt/Boldt-1B
Boldt-1B-IT-Preview
Boldt-1B-IT-Preview is a preview of an instruction-tuned German language model, fine-tuned on top of Boldt-1B. It is part of the Boldt series of German Small Language Models (SLMs) trained from scratch at Humboldt-Universität zu Berlin.
- Boldt-DC-350M
- Boldt-DC-1B
- Boldt-1B
- Boldt-1B-IT-Preview (this model)
Preview status. This is an early release intended to demonstrate instruction-following capabilities emerging from our quality-focused pre-training recipe. It has not undergone systematic safety evaluation and should not be used in production settings without further assessment.
Training data
Boldt-1B-IT-Preview was fine-tuned on a curated mixture of 95k German instruction-output pairs from four sources:
- Aya: German subset of the Aya dataset, consisting of approximately 200 human-authored instruction-output pairs.
- SmolTalk2 (DE, improved): an improved German subset of the SmolTalk2 dataset. We adjusted 52k prompts for more natural flowing German and regenerated outputs using Qwen-3.6-27B to improve their quality.
- r/FragReddit: 7k prompts sourced from the r/FragReddit subreddit. Outputs were generated using Qwen-3.6-27B.
- Synthetic Reddit: 19k synthetic QA pairs derived from a dump of r/FragReddit posts. We used Qwen-3.6-27B to filter useful posts, rephrase questions for clarity, and generate helpful and educational answers.
- NER instructions: 17k NER tasks derived from 2 German NER datasets.
The mixture is designed to combine broad topical coverage with naturalness of German expression, complementing the information-dense pre-training corpus underlying the base model.
Usage
Boldt-1B-IT-Preview is designed for single-turn German-language instruction-following tasks. It was not fine-tuned for multi-turn conversations, and performance in multi-turn settings is not guaranteed. It uses a standard chat template and can be used as follows:
from transformers import AutoTokenizer, AutoModelForCausalLM
model_name = "Boldt/Boldt-1B-IT-Preview"
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(model_name)
messages = [
{"role": "user", "content": "Erkläre mir kurz, wie Quantencomputer funktionieren."}
]
input_ids = tokenizer.apply_chat_template(
messages,
tokenize=True,
add_generation_prompt=True,
return_tensors="pt"
)
outputs = model.generate(
input_ids,
max_new_tokens=256,
do_sample=True,
temperature=0.7,
top_p=0.9,
)
print(tokenizer.decode(outputs[0][input_ids.shape[-1]:], skip_special_tokens=True))
Limitations
- Language: This model is optimized for German. Other languages are not supported.
- Preview status: This model is released as a research preview. It may produce factually incorrect or inconsistent outputs. Not optimized for multi-turn dialogue.
- Safety: We have not conducted systematic evaluations for toxic content, demographic biases, or harmful stereotypes. Quality filtering during pre-training may reduce some risks relative to unfiltered corpora but cannot eliminate them. Repeated multi-epoch exposure may amplify encoded biases. Users should exercise caution in sensitive applications.
Citation
@misc{boldt,
title={Repetition over Diversity: High-Signal Data Filtering for Sample-Efficient German Language Modeling},
author={Ansar Aynetdinov and Patrick Haller and Alan Akbik},
year={2026},
eprint={2604.28075},
archivePrefix={arXiv},
primaryClass={cs.CL},
url={https://arxiv.org/abs/2604.28075},
}