Mistral Medium 3.5 vs o3
Mistral Mistral Medium 3.5 | OpenAI o3 | |
|---|---|---|
| Overview | ||
| Company | Mistral | OpenAI |
| Release date | Apr 29 2026 | Apr 16 2025 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 128B | — |
Context window | 256k | — |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | — | 26% |
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% | — |
| Timeline | ||
| Release gap | o3 shipped 378 days before Mistral Medium 3.5 | |
Which is better: Mistral Medium 3.5 or o3?
Mistral Medium 3.5 and o3 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. o3 shipped 378 days before Mistral Medium 3.5, so benchmark comparisons should account for the intervening progress.
Mistral Medium 3.5 is open weight, while o3 is proprietary.
Direct benchmark comparisons are unavailable — Mistral Medium 3.5 and o3 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.
o3 was released by OpenAI on Apr 16 2025.
Mistral Medium 3.5 is an open weight model released by Mistral. o3 is a proprietary model released by OpenAI.
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