Qwen3-8B-SFT-Math-Multilingual

Qwen3-8B that reasons in the language of the problem

arXiv: 2609.37104 base: Qwen3-8B stage: SFT languages: 6 license: Apache 2.0

Bar chart, non-English mean, released Qwen3-8B against the SFT model. Reasoning in the requested language 27% and 100%. Did not finish 6% and 18%. Delivered 20% and 65%.

Mean over Chinese, Spanish, French, Arabic and Russian · 70 problems × 16 samples per language

  • What it is. Qwen3-8B after full-parameter fine-tuning on SFT-Math-Multilingual-56k: 56,307 long chain-of-thought math solutions in six languages. Epoch-1 checkpoint.
  • What it fixes. Reasoning follows the requested language in 99.7% of non-English responses, up from 26.9%; best-of-16 delivery goes from 30.6% to 86.3%.
  • What to know. It replicates the 4B result at a second size. No RL stage was run at 8B, so 18.2% of non-English responses still loop.

Results

Released SFT
Answer correct 78.1% 66.0%
Reasoning in the requested language 26.9% 99.7%
Did not finish 5.8% 18.2%
Delivered (J@1) 19.6% 65.1%
Delivered, best of 16 (J@16) 30.6% 86.3%
Median response, tokens 6,829 7,172

70 competition problems (30 AIME-2026 + 40 AMC-2023) per language from Multilingual-Math-Reasoning-Eval, 16 samples each at temperature 0.7, 24,576-token budget. A response is delivered when the answer is correct, the visible reasoning is in the requested language, and it terminates (J = C ∧ L ∧ T, scored per response). Tables show the mean over Chinese, Spanish, French, Arabic and Russian.

Per language
Correct In language Did not finish J@1 J@16 Median tokens
English 74.8% 100.0% 2.9% 74.7% 94.3% 5,562
Chinese 64.8% 99.7% 18.6% 64.4% 85.7% 5,744
Spanish 68.5% 99.8% 9.2% 68.4% 88.6% 6,548
French 67.3% 98.9% 13.5% 67.1% 84.3% 7,090
Arabic 62.0% 99.9% 29.3% 60.2% 85.7% 8,382
Russian 67.5% 100.0% 20.4% 65.2% 87.1% 8,096

Quick start

from datasets import load_dataset
from transformers import AutoModelForCausalLM, AutoTokenizer

name = "96kevinli29/Qwen3-8B-SFT-Math-Multilingual"
tok = AutoTokenizer.from_pretrained(name)
model = AutoModelForCausalLM.from_pretrained(name, torch_dtype="auto", device_map="auto")

# a French problem with a French instruction: "…en raisonnant entièrement en français."
prompt = load_dataset("96kevinli29/Multilingual-Math-Reasoning-Eval", "fr")["amc23"][0]["prompt"]
text = tok.apply_chat_template([{"role": "user", "content": prompt}], tokenize=False, add_generation_prompt=True)
inputs = tok(text, return_tensors="pt").to(model.device)
out = model.generate(**inputs, max_new_tokens=24576, do_sample=True, temperature=0.7)
print(tok.decode(out[0][inputs.input_ids.shape[1]:], skip_special_tokens=True))

Qwen3 chat template with thinking on; the reasoning appears inside <think> … </think>. Give hard problems a large max_new_tokens. Loads with transformers 4.x and 5.x.

Prompt format in six languages
Instruction that opens the user turn
English Solve the following math problem step by step, reasoning entirely in English.
Chinese 请全程用中文逐步推理并解决以下数学问题。
Spanish Resuelve el siguiente problema matemático paso a paso, razonando enteramente en español.
French Résous le problème de mathématiques suivant étape par étape, en raisonnant entièrement en français.
Arabic حل المسألة الرياضية التالية خطوة بخطوة مع التفكير بالكامل باللغة العربية.
Russian Решите следующую математическую задачу шаг за шагом, рассуждая полностью на русском языке.

The full prompts (instruction, problem and answer format, all in the target language) are in the evaluation set.

Model family

Stage Checkpoint
I · Release Qwen/Qwen3-4B · Qwen/Qwen3-8B solves the problem, reasons in English
II · SFT Qwen3-4B-SFT-Math-Multilingual reasons in the requested language, sometimes loops
II · SFT Qwen3-8B-SFT-Math-Multilingual ← this model the same result at 8B
III · RL Qwen3-4B-MathRL-Multilingual-Gated keeps the language, stops the looping
III · RL Qwen3-4B-MathRL-Multilingual-Additive keeps the language, stops the looping

Data: SFT-Math-Multilingual-43k · SFT-Math-Multilingual-56k · DAPO-Math-Multilingual-6Lang · Multilingual-Math-Reasoning-Eval

Training

Same translate-and-filter pipeline as the 4B corpus, on a separately built 56K set from OpenR1-Math. 2 epochs configured; epoch 1 is released. Code: base-model-sft-verl.

Full recipe
Objective token-level cross-entropy over the whole response, reasoning included
Optimizer AdamW, lr 2e-5 with cosine decay to 0.1×, warmup ratio 0.01, weight decay 0.1
Batch · context 16 traces · up to 32,768 tokens
Precision · clip bfloat16 · gradient clip 1.0
Hardware 16 × A100-40GB on 4 nodes, MeluXina (LuxProvide)
Framework verl SFT trainer, FSDP, full-parameter

Limitations

  • Looping: 18.2% of non-English responses do not finish within 24,576 tokens (29.3% in Arabic).
  • Accuracy is below the released Qwen3-8B on the same problems (78.1% → 66.0%).
  • Mathematics and six languages only; machine-translated training data; one seed.

Citation

@article{li2026posttraining,
  title   = {What Does Post-Training Change in Multilingual Reasoning?},
  author  = {Li, Hongyang and Li, Xiao and Wu, Caesar and Danoy, Gr{\'e}goire and Bouvry, Pascal},
  journal = {arXiv preprint arXiv:2609.37104},
  year    = {2026}
}

@misc{qwen3-8b-sft-math-multilingual-2026,
  title        = {{Qwen3-8B-SFT-Math-Multilingual}: six-language long chain-of-thought math SFT of {Qwen3-8B}},
  author       = {Li, Hongyang and Li, Xiao and Wu, Caesar and Danoy, Gr{\'e}goire and Bouvry, Pascal and {Sea-Fill Community}},
  year         = {2026},
  publisher    = {Hugging Face},
  howpublished = {\url{https://huggingface.co/96kevinli29/Qwen3-8B-SFT-Math-Multilingual}},
  note         = {Maintained by Sea-Fill Community.}
}

Built and released by the authors together with the Sea-Fill Community, which maintains this release.

Downloads last month
47
Safetensors
Model size
8B params
Tensor type
BF16
·
Inference Providers NEW
This model isn't deployed by any Inference Provider. 🙋 Ask for provider support

Model tree for 96kevinli29/Qwen3-8B-SFT-Math-Multilingual

Finetuned
Qwen/Qwen3-8B
Finetuned
(2,335)
this model

Datasets used to train 96kevinli29/Qwen3-8B-SFT-Math-Multilingual

Paper for 96kevinli29/Qwen3-8B-SFT-Math-Multilingual

Evaluation results

  • Delivered J@1 (correct, in the requested language, terminated) on AIME-2026 + AMC-2023, five non-English languages (zh, es, fr, ar, ru)
    self-reported
    65.100
  • Answer accuracy on AIME-2026 + AMC-2023, five non-English languages (zh, es, fr, ar, ru)
    self-reported
    66.000
  • Reasoning in the requested language on AIME-2026 + AMC-2023, five non-English languages (zh, es, fr, ar, ru)
    self-reported
    99.700