Mistral Large 4 changelog

Every confirmed milestone for Mistral Large 4 ("Le Chonk"), from the October 6, 2026 public preview announcement to the expected late-October open weights. Entries are added only when Mistral AI or a reputable outlet confirms them.

• October 6, 2026

  Public preview launch

  Mistral AI announced Mistral Large 4 ("Le Chonk") as a public preview. Key details from the announcement:

  • 1.05T total parameters with 49B active per token (MoE), 1M-token context, native multimodal.
  • Available via the Mistral API at $1.36 per 1M input tokens and $4.18 per 1M output tokens.
  • Documentation released as version 26.10, with a playground available on the docs/models page.
• October 27, 2026

  Open weights expected upcoming / reported

  Reuters reported that the open weights are expected to land on October 27, 2026; Mistral AI has said "end of October". Expected under a custom Mistral license and expected on Hugging Face.

• Late October 2026

  Broader public rollout upcoming

  After the initial staged preview group (developers, cybersecurity professionals, and government authorities), broader public access is expected later in October 2026.

• Ongoing

  RL tuning of the final checkpoint in progress

  Mistral AI is continuing reinforcement learning to tune the final checkpoint before the weights go live. Co-founder and chief scientist Guillaume Lample expects capabilities to improve as RL concludes and training capacity expands.