# Mistral releases the weights of Mistral Large 4 (Le Chonk), a 1T-parameter multimodal MoE model

Canonical: https://theagenticweekly.com/news/mistral-large-4-open-weights · Evidence: Reported · First seen: 2026-10-29 14:15 UTC · Source published: 2026-10-29 12:00 UTC · Brief published: 2026-10-29 14:27 UTC · Updated: 2026-10-29 14:27 UTC · Author: Agentic Weekly

> On Oct 29, 2026 Mistral released the weights of an improved Mistral Large 4 (Le Chonk), a multimodal mixture-of-experts model with about 1T total parameters and a 1M-token context, under the Mistral Ecosystem Open-Weight License. Mistral calls it the best open-weight model for coding.

## What changed

- Mistral released the weights of Mistral Large 4 (Le Chonk), three weeks after the model entered public preview. Mistral says the released model is improved by further reinforcement learning, mainly in coding and defensive cybersecurity.
- Hugging Face describes it as a multimodal Mixture-of-Experts model that takes text and images and outputs text, with about 1T total parameters and a 1M-token context, shipped as FP8 and NVFP4 checkpoints under the Mistral Ecosystem Open-Weight License.
- Hugging Face says the license is an MIT derivative that sets limitations for model-as-a-service offerings, and that the model has day-0 support in transformers, vLLM and llama.cpp, plus TRL fine-tuning, Inference Endpoints and GGUF quants.
- The model now has three reasoning modes, low, medium and high (the default); Mistral says low replaces the old None mode, and Hugging Face notes reasoning cannot be turned off.
- Mistral's own benchmark claims: 19.7% on Cognition's private FrontierCode 2.0, 41% on Terminal-Bench 4.0 (up 13 points from the preview), 48% on the Artificial Analysis Coding Agent Index and 51% on the Artificial Analysis Cyber Index.
- Mistral says a specialized cybersecurity variant for penetration testing and red-teaming is in preview only for vetted enterprise design partners, and that it is tightening guardrails after seeing potential uplift for real attacks.

## In the source's words

> "Today, we're releasing the weights of this improved Mistral Large 4."
> (Mistral AI, announcement post, https://mistral.ai/news/mistral-large-4-oss/)

> "It’s distributed under the Mistral Ecosystem Open-Weight License (an MIT derivative that establishes limitations for model-as-a-service offerings)."
> (Hugging Face blog, https://huggingface.co/blog/mistral-large4)

> "Though we observed the model refusing to comply with black-box attacks against live targets, we see a potential for uplift to conduct real attacks."
> (Mistral AI, announcement post, https://mistral.ai/news/mistral-large-4-oss/)

## What we have not verified

- We did not download or run the model; this brief is Reported from Mistral's post and the Hugging Face blog.
- All benchmark numbers are vendor claims we did not reproduce. The sources also frame cyber results differently: Mistral cites 51% on the Artificial Analysis Cyber Index, while Hugging Face cites 82% on its reproduce-and-patch task.
- Active parameter counts differ by source: Hugging Face says 49B active, while the checkpoint name (A52B) and Mistral's preview docs say 52B. We did not read the full license text.
- Neither post says whether API pricing or the API's preview status changed with the weights release.

## Timeline

- Source published: 2026-10-29 12:00 UTC
- First seen by our watcher: 2026-10-29 14:15 UTC (via Mistral AI news feed)
- Brief published: 2026-10-29 14:27 UTC

## Sources

- [Mistral AI: Mistral Large 4 (Le Chonk) is now open weight](https://mistral.ai/news/mistral-large-4-oss/) (primary source) (fetched 2026-10-29)
- [Hugging Face blog: Welcome Le Chonk](https://huggingface.co/blog/mistral-large4) (primary source) (fetched 2026-10-29)

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## How to cite

Agentic Weekly, "Mistral releases the weights of Mistral Large 4 (Le Chonk), a 1T-parameter multimodal MoE model", published 2026-10-29 14:27 UTC, https://theagenticweekly.com/news/mistral-large-4-open-weights