Sunday, October 18, 2026
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Mistral AI Unveils Mistral Large 4, a 1.05-Trillion Parameter Multimodal Model

Mistral AI's new flagship model, nicknamed 'Le Chonk,' combines massive scale with a 1M token context window and strong cybersecurity performance.

A Giant Among Open Models

Mistral AI has announced the release of Mistral Large 4, internally dubbed "Le Chonk," as a public preview on October 6, 2026 1. The model is a granular Mixture of Experts (MoE) architecture with a staggering 1.05 trillion total parameters, though only 49 billion are activated per token . It also features a 1.6-billion-parameter vision encoder and supports a 1 million token context window, making it one of the most capable multimodal models available today .

What makes this architecture efficient is that only about 4.7% of the total weights activate for each token processed. This means the model can serve at mid-tier pricing while carrying the knowledge capacity of a trillion-parameter class system 1. The full 1.05 trillion parameters still need to reside in memory, but the lower active count controls compute costs rather than hardware bills .

Where It Trains and What It Knows

Mistral Large 4 was trained from scratch on 3,800 NVIDIA Grace Blackwell GPUs inside Mistral's own European datacenters 1. The training data covered more than 160 languages, including every official language of the European Union . The model natively accepts image input alongside text, marking it as a true multimodal system rather than a text model with an add-on vision component .

The API is now live at a preview price of $1.36 per million input tokens and $4.18 per million output tokens 1. However, the full model weights will not be available until the end of October 2026, meaning self-hosting is not yet possible . The license has also not been announced .

Strong Performance in Cybersecurity

One of the model's standout areas is cybersecurity. Mistral AI reports that Mistral Large 4 scored 93% on Cybench and 82% on CyberGym-E2E, placing it in the global top 5 on the Artificial Analysis Cyber Index 1. More notably, Mistral claims several closed frontier models score near zero on CyberGym-E2E because they refuse to attempt the tasks at all . Reproducing vulnerabilities is standard defensive cybersecurity work, and provider-level refusals can block that process .

In agentic coding benchmarks, the model achieved 61.7% on DeepSWE v1.1, 59.4% on SWE-Atlas-QnA, and 28.3% on Terminal-Bench 4.0, earning a combined Coding Agent Index score of 49.8 1. Mistral notes these evaluations were run privately before the benchmarks went public, so they are not yet independently reproducible . In blind human evaluations by Surge AI, annotators rated Mistral Large 4 Preview at 3.74 out of 5, placing it second among five models tested, behind Claude Opus 5 which scored 4.22 .

On the safety front, the model resisted 93.3% of attacks on Lakera's B3 benchmark and scored 1.691 out of 2.0 on KORABench 1.

Rivals in the Arena

When compared to other open-weight models like DeepSeek V4 Pro, Kimi K3, and GLM-5.3, Mistral Large 4 holds its own with the largest active parameter count among its peers and native image understanding 1. The model supports function calling, structured outputs, document Q&A, batching, and Agents and Conversations endpoints . Cached input is priced at just $0.14 per million tokens, which significantly improves the economics of running long-context agent workflows .

Full details and documentation are available through the Mistral Large 4 announcement and model docs 1.

Key facts

  • Mistral Large 4 has 1.05 trillion total parameters with 49 billion active per token
  • It features a 1 million token context window and native image input
  • Trained on 3,800 NVIDIA Grace Blackwell GPUs in Mistral's European datacenters
  • Scores 93% on Cybench and 82% on CyberGym-E2E in cybersecurity benchmarks
  • API is live now; full weights expected by end of October 2026

Sources

  1. Mistral AI Releases Mistral Large 4 (Le Chonk): A 1.05T Parameter Multimodal MoE Model — marktechpost.com