Mistral Medium 3.5vsComposer 1.5
Mistral Medium 3.5 | Composer 1.5 | |
|---|---|---|
| Specifications | ||
Parameters | 128B | — |
Context window | 256k | — |
| Benchmarks | ||
Coding SWE-Bench VerifiedReal coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 77.6% | — |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | — | 67% |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | 1267 | — |
| Overview | ||
| Company | Mistral | SpaceXAI |
| Release date | Apr 29 2026 | Feb 9 2026 |
| Access | Open Weight | Proprietary |
Which is better: Mistral Medium 3.5 or Composer 1.5?
Mistral Medium 3.5 and Composer 1.5 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Composer 1.5 shipped 79 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.
Mistral Medium 3.5 is open weight, while Composer 1.5 is proprietary.
Direct benchmark comparisons are unavailable — Mistral Medium 3.5 and Composer 1.5 don't publish scores on any of the same benchmarks.
Frequently asked questions
Mistral Medium 3.5 was released by Mistral on Apr 29 2026.
Composer 1.5 was released by SpaceXAI on Feb 9 2026.
Mistral Medium 3.5 is an open weight model released by Mistral. Composer 1.5 is a proprietary model released by SpaceXAI.
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