Mistral Medium 3.5

Mistral AI · open weight · mistral-medium-3-5

Mistral Medium 3.5 is Mistral AI's first flagship merged model: a dense 128B-parameter multimodal model with a 256k context window that unifies instruction-following, reasoning, and coding capabilities in a single set of weights. It replaces Mistral Medium 3.1 and Magistral in Le Chat, and Devstral 2 in the Vibe coding agent. Reasoning effort is configurable per request, and the vision encoder was trained from scratch to handle variable image sizes and aspect ratios. Released as open weights under a Modified MIT License.