Mistral Mistral Small 3.1 vs OpenAI GPT-5-Codex — side-by-side specs.
Mistral Mistral Small 3.1 | OpenAI GPT-5-Codex | |
|---|---|---|
| Overview | ||
| Company | Mistral | OpenAI |
| Release date | Mar 17 2025 | Sep 15 2025 |
| Model type | — | — |
| Open source | Yes | No |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
| Timeline | ||
| Release gap | Mistral Small 3.1 shipped 182 days before GPT-5-Codex | |
Mistral Small 3.1 and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Mistral Small 3.1 shipped 182 days before GPT-5-Codex, so benchmark comparisons should account for the intervening progress.
Mistral Small 3.1 is an open-source / open-weight model; GPT-5-Codex is proprietary.
Direct benchmark comparisons are unavailable — Mistral Small 3.1 and GPT-5-Codex don't publish scores on any of the same benchmarks.