Inter-office memo
- To
- Everyone trying open coding models
- From
- Mo, Chief Executive
- Date
- October 29, 2026, 4:04 PM CDT
- Re
- Mistral Large 4 open weights
Mistral Large 4’s weights are out. What it takes to run, and how to use it now
On October 29, 2026, Mistral released the weights of Mistral Large 4 on Hugging Face, under a modified MIT license that allows commercial use. At about 1 trillion parameters, it won’t run on a laptop: the smallest build is 233 GB. Most people will use it in Mistral Vibe or on Mistral’s API, at $0.70 in and $2.10 out per million tokens.
What Mistral released
On October 29, 2026, Mistral released the weights of Mistral Large 4, the model it nicknames Le Chonk: “We release the weights of Le Chonk, advancing the frontier of open models in agentic coding and cybersecurity.” The model came out as an API-only public preview on October 6, and The Next Web reports that it had three more weeks of reinforcement learning before the weights went out, so the download isn’t the preview.
The model card on Hugging Face describes a mixture-of-experts model with about 1 trillion parameters, of which about 52 billion are active for each token (49 billion without the embedding and output layers). It reads text and images, writes text, and has a 1M-token context. It has three reasoning efforts, set with reasoning_effort: low, medium and high, the default.
The weights come under the Mistral Ecosystem Open-Weight License, which Mistral calls a modified MIT license. You may use, change, fine-tune and sell with it. The one catch: a business offering “a third party access to the Model or its derivative works for inference or post-training” must “enter into a separate commercial license with Mistral.” Internal use is exempt, as is use through Mistral’s own products. There’s no revenue threshold.
How good it is
These are Mistral’s own figures, from its announcement and as The Next Web reports them, except the last row, which is Artificial Analysis’s:
| Test | Mistral Large 4 | Compared with |
|---|---|---|
| Terminal-Bench 4.0 | 41% (28% at preview) | GLM-5.3, 40% |
| Artificial Analysis Coding Agent Index | 48% | GLM-5.3, effectively tied |
| Artificial Analysis Cyber Index | 51% | |
| Malicious cyber requests refused | 96.6% | Highest of the open models Mistral measured |
| Coding Agent Index, in Mistral Vibe (Artificial Analysis) | 48.3 at high effort, $1.26 a task | Claude Code with Opus 5.5 leads |
Mistral says it uses 47% fewer tokens per task than GLM-5.3 on the Coding Agent Index, and that in Surge’s human-preference test of coding it ranked behind only Claude Opus 5.5. On Artificial Analysis’s index, as our memo on it sets out, Mistral Vibe with Large 4 sits below the top ten, at 35.4 on medium effort. It’s a strong open model for coding, not a replacement for the best closed ones.
What it takes to run
More than any laptop or desktop has. Mistral’s serving examples on the model card run on eight GPUs, with --tensor-parallel-size 8 in vLLM and --tp-size 8 in SGLang, and there’s an NVFP4 build for Nvidia’s Blackwell GPUs. The Next Web reports that a quantized version runs on four Nvidia B200 or B300 GPUs.
For the rest of us, Unsloth’s GGUF builds work with llama.cpp, Ollama and LM Studio:
| Build | Size | Unsloth’s guidance |
|---|---|---|
| 1-bit (UD-IQ1_S) | 233 GB | A device with 256 GB of memory |
| 2-bit | 302 to 378 GB | 384 to 512 GB |
| 4-bit (UD-Q4_K_XL) | 605 GB | |
| 8-bit (Q8_0) | 1.12 TB | 1.2 TB or more |
Unsloth’s Ollama command for the 4-bit build is ollama run hf.co/unsloth/Mistral-Large-4-1T-A52B-GGUF:UD-Q4_K_XL. Mistral says Large 4 “will serve as the foundation” for smaller, specialized models, and The Next Web reports that distilled versions will follow “in the coming months,” including one that runs on a laptop, without a date.
Four ways to use it in a coding agent
- Mistral Vibe. Mistral’s own coding agent, and the setup Artificial Analysis tested. Mistral says to try Large 4 “in Vibe Code; give it a feature to build or a bug to fix in your own repository.” The CLI installs with
curl -LsSf https://mistral.ai/vibe/install.sh | bash(docs). On Mistral’s pricing page, the free plan has “limited access to Vibe,” and Pro, at $14.99 a month, has “full access to Vibe for all-day coding and long-running tasks,” with $15 of API credits. - Mistral’s API, per token. The model is
mistral-large-4-0at $0.70 per million input tokens, $0.07 cached and $2.10 output (model card): about a third of Claude Sonnet 5.5’s or GPT-6.1 Sol’s $2 input price, and a fifth of their $10 output price. OpenCode doesn’t list Mistral as a provider yet, so add it as a custom OpenAI-compatible provider, as OpenCode’s provider guide describes. Mistral also lists it on OpenRouter, which OpenCode does list, though its page today showed only EU routing through Mistral. - Your own servers. Serve the weights with vLLM or SGLang from the model card, or llama.cpp with Unsloth’s builds, and point an agent at the server’s OpenAI-compatible address. OpenCode’s guide covers Ollama at
http://localhost:11434/v1and llama.cpp athttp://127.0.0.1:8080/v1. - Hosted elsewhere. Mistral says Large 4 is also on Nvidia-hosted endpoints and Microsoft Foundry.
Enjoy runs OpenCode beside Claude Code, Codex and the other labs’ agents. Set up Mistral’s API or your own server in OpenCode once, and Mistral Large 4 appears in Enjoy’s model picker with the rest of OpenCode’s models. Hand it a conversation when a Claude or ChatGPT plan runs low, or give it the same task to compare. With a model you serve yourself, the work stays on your machines. Enjoy is a monthly subscription, with the first seven days free (pricing); Enjoy doesn’t add Mistral to a Claude or ChatGPT account.
What Mistral hasn’t said
- What it takes to run. The model card gives no memory figure; the hardware above is from Unsloth and The Next Web.
- When the smaller versions come, or how small they’ll be.
- Which Vibe plan gets how much Large 4. The pricing page doesn’t mention the model.
- The technical report, which Mistral lists as “coming soon.”
We’ll update this memo when Mistral publishes the smaller versions.
6.Questions.
Is Mistral Large 4 open source?
- Its weights are open. They’re on Hugging Face under the Mistral Ecosystem Open-Weight License, a modified MIT license that allows use, changes, fine-tuning and commercial use. The one condition is that a business offering the model to others as a service needs a separate commercial license from Mistral; internal use is exempt.
Can I run Mistral Large 4 on my own computer?
- Not on a laptop. Unsloth’s smallest build is 233 GB and is meant for a machine with 256 GB of memory; its 4-bit build is 605 GB. Mistral’s own serving examples use eight GPUs. For a coding model that fits on a laptop, see Flint.
How much does Mistral Large 4 cost?
- $0.70 per million input tokens and $2.10 per million output tokens on Mistral’s API, with cached input at $0.07. Against Claude Sonnet 5.5 or GPT-6.1 Sol, at $2 and $10, that’s about a third of the input price and a fifth of the output price. Running the weights yourself costs only your hardware.
Is Mistral Large 4 better than GLM-5.3?
- About even on coding. Mistral’s figures, as The Next Web reports them, put it at 41% on Terminal-Bench 4.0 to GLM-5.3’s 40%, and on Artificial Analysis’s Coding Agent Index it scores 48.3 in Mistral Vibe to GLM-5.3’s 48.9 in OpenCode, using fewer tokens. It is well behind Claude Opus 5.5.
How do I use Mistral Large 4 in a coding agent?
- The quickest way is Mistral’s own Vibe, which has a free tier. You can also add Mistral’s API, or a copy you serve yourself, to OpenCode as a custom provider, and Enjoy then shows it in its model picker beside your other agents.