README.md

---
language:
- fr
- en
library_name: transformers
tags:
- dpo
- post-training
- french
- alignment
- model-merging
- qwen3
- chocolatine
- comparia
license: apache-2.0
base_model: Qwen/Qwen3-4B-Instruct-2507
datasets:
- jpacifico/comparia-dpo-pairs-bt-6k
- jpacifico/french-orca-dpo-pairs-revised
---

# Chocolatine-2-4B-Instruct-DPO-v2.1

**Chocolatine-2-4B-Instruct-DPO-v2.1** is a post-trained version of [Qwen/Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507), designed to improve instruction-following, reasoning, and overall performance in French, while preserving strong multilingual capabilities.  
In my evaluation setup, it delivers consistent gains across the tested French benchmarks, pointing to a broad improvement in French capabilities.  
Although the post-training pipeline focuses on French preference data, no degradation is observed on English tasks, and slight improvements are sometimes seen, suggesting positive cross-lingual transfer.  
Optimized variants (MLX, GGUF) are also available, making the model particularly suitable for local inference.  


## Model Overview

- **Base model:** Qwen/Qwen3-4B-Instruct-2507
- **Parameters:** 4.0B
- **Context Length:** 262,144 natively
- **Post training methods:** DPO + Model Merging

Note: This model supports only non-thinking mode and does not generate `<think></think>` blocks in its outputs.  
This design is consistent with the goals of the post-training setup, which favors a compact dense instruct model focused on direct generation efficiency and practical downstream use.    
For use cases requiring explicit reasoning traces or structured thinking outputs, Qwen/Qwen3.5-4B (thinking mode) is recommended.

**Model Variants**

- Chocolatine-2-4B-Instruct-DPO-v2.1 (this repo): Contains the retrainable weights in BF16 format
- Quantized GGUF versions : [Q4_K_M](https://huggingface.co/jpacifico/Chocolatine-2-4B-Instruct-DPO-v2.1-Q4_K_M-GGUF) / [Q8_0](https://huggingface.co/jpacifico/Chocolatine-2-4B-Instruct-DPO-v2.1-Q8_0-GGUF) and more from mradermacher [here](https://huggingface.co/mradermacher/Chocolatine-2-4B-Instruct-DPO-v2.1-GGUF)
- MLX (optimized for Apple silicon): [4Bit](https://huggingface.co/jpacifico/Chocolatine-2-4B-Instruct-DPO-v2.1-mlx-4Bit) / [6Bit](https://huggingface.co/jpacifico/Chocolatine-2-4B-Instruct-DPO-v2.1-mlx-8Bit)

**Ollama** : In addition to the Hugging Face release, quantized 4-bit and 8-bit variants are also available [here](https://ollama.com/jpacifico/chocolatine-2.1) on Ollama for convenient local inference.

## Benchmarks

The results indicate a consistent improvement across the tested French benchmarks, covering several capability types. This suggests a broad gain in French performance, while English results remain overall stable.

| Benchmark fr | Qwen3-4B-Instruct-2507 (base) | Chocolatine-2-4B-Instruct-DPO-v2.1 |
|---|---:|---:|
| gpqa-fr:diamond | 28.93 | **32.49** |
| french_bench_arc_challenge | 47.13 | **49.79** |
| french_bench_grammar | 70.59 | **72.27** |
| french_bench_boolqa | 88.76 | **89.89** |
| french_bench_hellaswag | 56.99 | **58.03** |
| global_mmlu_fr | 63.75 | **64.75** |
| xwinograd_fr | 66.27 | **67.47** |
| fr_mt_bench | 6.22 | **6.44** |

*FR-MT-Bench* evaluation is performed on [MT-Bench-French](https://huggingface.co/datasets/bofenghuang/mt-bench-french), using [multilingual-mt-bench](https://github.com/jpacifico/multilingual_mt_bench) with OpenAI/GPT-5 as the LLM judge.  
*global_mmlu_fr*, *xwinograd_fr* and *french_bench* results were obtained using [EleutherAI LM Eval Harness](https://github.com/EleutherAI/lm-evaluation-harness) in a **0-shot** evaluation setting.  
*gpqa-fr:diamond* using LightEval/vLLM via [kurakurai/Luth](https://github.com/kurakurai/Luth.git) process eval.

| Benchmark eng | Qwen3-4B-Instruct-2507 (base) | Chocolatine-2-4B-Instruct-DPO-v2.1 |
|---|---:|---:|
| arc_challenge | **58.79** | 58.45 |
| hellaswag | 69.08 | **70.16** |
| boolq | 84.80 | **85.32** |
| gpqa_diamond_zeroshot | **38.89** | 38.38 |

English benchmark results were obtained using [EleutherAI LM Eval Harness](https://github.com/EleutherAI/lm-evaluation-harness) in a **0-shot** evaluation setting.

## Training & Alignment Pipeline  

Chocolatine-2-4B-Instruct-DPO-v2.1 is derived from [Qwen/Qwen3-4B-Instruct-2507](https://huggingface.co/Qwen/Qwen3-4B-Instruct-2507) using a multi-step post-training pipeline:

**Stage 1 – DPO (Compar:IA adaptation)**

Direct Preference Optimization (DPO) on a DPO-adapted version of **[Compar:IA](https://comparia.beta.gouv.fr/datasets)** data, derived from the preference dataset [comparia-votes](https://huggingface.co/datasets/ministere-culture/comparia-votes), part of a public initiative led by the Ministry of Culture (French gov). Previous iterations of the Chocolatine model series also were selected as part of this initiative.  
I constructed an original DPO dataset from these votes by transforming them into preference pairs (chosen / rejected), with additional filtering and formatting steps to make them suitable for DPO fine-tuning.  
Two dataset variants were created ([6k](https://huggingface.co/datasets/jpacifico/comparia-dpo-pairs-bt-6k) and [13k](https://huggingface.co/datasets/jpacifico/comparia-dpo-pairs-bt-13k) preference pairs).  
The **6k variant** was used for the DPO training reported in this release.

**Stage 2 – DPO (French-ORCA pairs)**

A second DPO stage using a french-version of ORCA preference pairs, based on the dataset **[jpacifico/french-orca-dpo-pairs-revised](https://huggingface.co/datasets/jpacifico/french-orca-dpo-pairs-revised)**, commonly used in the Chocolatine training pipeline.  
This stage further improves : general instruction alignment, robustness across tasks, cross-lingual capabilities. 

**Stage 3 – Model Merging (MergeKit + TIES)**

The resulting checkpoints were merged using **MergeKit** with the TIES method.

TIES merging: selects task-relevant parameter updates, reduces destructive interference between models and preserves base model stability.

MergeKit configuration:

```yaml
# ties2 recipe
models:
  - model: jpacifico/Qwen3-4B-Instruct-DPO-test2
    parameters:
      density: 0.5
      weight: 0.5
  - model: jpacifico/Qwen3-4B-Instruct-DPO-test-b3
    parameters:
      density: 0.5
      weight: 0.5

merge_method: ties
base_model: Qwen/Qwen3-4B-Instruct-2507

parameters:
  normalize: false
  int8_mask: true

dtype: bfloat16
```

## Usage

The following contains a code snippet illustrating how to use the model generate content based on given inputs.  
```python
from transformers import AutoModelForCausalLM, AutoTokenizer

model_name = "jpacifico/Chocolatine-2-4B-Instruct-DPO-v2.1"

# load the tokenizer and the model
tokenizer = AutoTokenizer.from_pretrained(model_name)
model = AutoModelForCausalLM.from_pretrained(
    model_name,
    torch_dtype="auto",
    device_map="auto"
)

# prepare the model input
prompt = "Give me a short introduction to large language model."
messages = [
    {"role": "user", "content": prompt}
]
text = tokenizer.apply_chat_template(
    messages,
    tokenize=False,
    add_generation_prompt=True,
)
model_inputs = tokenizer([text], return_tensors="pt").to(model.device)

# conduct text completion
generated_ids = model.generate(
    **model_inputs,
    max_new_tokens=16384
)
output_ids = generated_ids[0][len(model_inputs.input_ids[0]):].tolist() 

content = tokenizer.decode(output_ids, skip_special_tokens=True)

print("content:", content)
```

## Limitations  

The Chocolatine-2 model series is a quick demonstration that a base model can be easily fine-tuned to achieve compelling performance.
It does not have any moderation mechanism.  

Developed by: Jonathan Pacifico, 2026   
Model type: LLM  
Language(s) (NLP): French, English  
License: Apache-2.0  

Made with ❤️ in France