Mistral Launches Large 4 Public Preview with 1 Trillion Parameters, Open Weights Due October 31

French AI company Mistral AI launched a public preview of Mistral Large 4 on October 6, 2026, a natively multimodal model with 1.05 trillion total parameters and 49 billion active parameters using a mixture-of-experts architecture, according to the company's announcement and model documentation. The model supports a 1 million token context window, text and image inputs, and was trained on data covering more than 160 languages including all official EU languages. API pricing starts at $0.68 per million input tokens. Mistral says it will release the model's weights openly by the end of October after completing additional red-team safety testing.

The launch puts Europe's most prominent AI developer in direct competition with US and Chinese frontier models at the 1-trillion parameter scale, with Mistral promoting the model's cybersecurity capabilities and scoring 82 percent on one Artificial Analysis Cyber Index test and 93 percent on Cybench's 40-challenge set, per company-reported results. The delayed weight release reflects heightened regulatory and security scrutiny of advanced AI models capable of discovering software vulnerabilities, following the EU AI Act's entry into force in August 2024 and growing concern over dual-use capabilities. Whether Mistral can maintain European regulatory approval while releasing weights for a model of this capability—especially given US pressure on allied governments to restrict frontier AI model access—remains the open question.

Sources

Mistral AI, Introducing Mistral Large 4, October 6, 2026, mistral.ai Xenospectrum, Mistral Large 4 Preview Launches With 1.05 Trillion Parameters: Pricing and Benchmarks, October 7, 2026, xenospectrum.com Vanderbilt Report, Mistral Large 4: Europe's 1-Trillion-Parameter Open-Weight AI Model Enters Public Preview, October 7, 2026, vanderbiltreport.com Artificial Intelligence News, Mistral AI launches Large 4 preview ahead of open-weight release, October 6, 2026, artificialintelligence-news.com