Mistral introduces Devstral Medium and open-source Devstral Small 1.1 coding models

Mistral has launched two updated coding models: Devstral Medium and Devstral Small 1.1. Devstral Small 1.1 is distributed under the Apache 2.0 license and is designed for agentic code generation, demonstrating robust generalization across prompts and scaffold types. The model achieves a 53.6% score on SWE-Bench Verified, establishing it as a leading open model without test-time scaling. The 24 billion parameter model introduces further upgrades in performance and versatility over its predecessor.

Devstral Small 1.1 integrates with tools like OpenHands, supporting Mistral function calling and XML formats for broader compatibility. It can be deployed locally to support autonomous software development. The model is released under an open-source license for public use and community contributions.

Devstral Medium targets enterprise use cases, achieving 61.6% on SWE-Bench Verified and outperforming Gemini 2.5 Pro and GPT-4.1 at a quarter of the cost. It’s available via API, supports private infrastructure deployment, and allows custom fine-tuning. Pricing matches existing Mistral rates.