GPT-5.6 Terra vs Mistral Large 3

Choose GPT-5.6 Terra if you want the everyday OpenAI default for agents — volume work with frontier-adjacent quality. Choose Mistral Large 3 if you want general-purpose open-weight agent work, especially in the EU.

In our editorial scoring, GPT-5.6 Terra leads in 4 of five dimensions (output quality, agentic ability, speed and reliability), while Mistral Large 3 leads in 1. On price, GPT-5.6 Terra runs about $6.25 per 1M tokens (blended) and is proprietary; Mistral Large 3 is about $0.80 and open-weight.

The model is half the story — the agent is the other half

The model picks the moves; the agent runs the loop, the tools, and the guardrails. Once you've chosen a model, see which agent gets the most out of it.