Mistral releases Mistral Large 4 weights under open license

Mistral has released the weights for Mistral Large 4, its trillion-parameter multimodal model also known as “Le Chonk.” The move lets organizations download, run, adapt, and fine-tune the model on their own infrastructure instead of relying solely on a hosted API.

In an official blog post, Mistral says the model is available under its Ecosystem Open-Weight license. The license permits use, modification, fine-tuning, and commercial deployment, but providers operating a model-as-a-service business need a separate commercial agreement.

The French AI company positions the release as an option for organizations with strict requirements around data residency, customization, and control. Mistral Large 4 can be downloaded from Hugging Face and served with tools such as vLLM or SGLang. It is also available through Mistral’s API, Microsoft Foundry, OpenRouter, and NVIDIA-hosted services.

New results after additional training

Mistral says three additional weeks of reinforcement learning improved the model’s coding efficiency and cybersecurity performance. On Terminal-Bench 4.0, the company reports a score of 41%, up from 28% during the public preview. It also says output tokens fell by 30% on that benchmark.

According to Mistral, Large 4 reaches 48% on the Artificial Analysis Coding Agent Index, close to GLM-5.3’s 49%, while using 47% fewer tokens per task on average. Radhika Rajkumar reports for ZDNET that the model’s overall index score remains one point below GLM-5.3, despite leading that rival on Terminal-Bench.

The company has also added low, medium, and high reasoning modes. High is the default setting for complex tasks, while the other options are intended to reduce cost and response time for simpler work.

For defensive cybersecurity, Mistral reports a 51% score on the Artificial Analysis Cyber Index and says the model refuses 96.6% of malicious cyber requests in its tests. The company acknowledges that it observed potential for the model to assist real attacks and says it is updating its safeguards. A specialized cybersecurity variant is being tested only with vetted enterprise partners in authorized environments.

Sources

• Mistral Large 4 (Le Chonk) is now Open Weight – Mistral AI
• Mistral’s Le Chonk is now a top open model for coding, ranking alongside Codex GPT-6.1 Terra – ZDNet