Anthropic Claude Opus 4.5 vs Mistral Devstral 2 (123B) — side-by-side specs.
Anthropic Claude Opus 4.5 | Mistral Devstral 2 (123B) | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Mistral |
| Release date | Nov 24 2025 | Dec 9 2025 |
| Model type | — | — |
| Open source | No | Yes |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| 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. | 80.9% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 87% | — |
| Timeline | ||
| Release gap | Claude Opus 4.5 shipped 15 days before Devstral 2 (123B) | |
Claude Opus 4.5 and Devstral 2 (123B) don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude Opus 4.5 shipped 15 days before Devstral 2 (123B), so benchmark comparisons should account for the intervening progress.
Devstral 2 (123B) is an open-source / open-weight model; Claude Opus 4.5 is proprietary.
Direct benchmark comparisons are unavailable — Claude Opus 4.5 and Devstral 2 (123B) don't publish scores on any of the same benchmarks.