Devstral Small vs GPT-5-Codex
Mistral Devstral Small | OpenAI GPT-5-Codex | |
|---|---|---|
| Overview | ||
| Company | Mistral | OpenAI |
| Release date | May 21 2025 | Sep 15 2025 |
| Access | Open Weight | Proprietary |
| Specifications | ||
Parameters | 24B | — |
| 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. | — | 39% |
| Timeline | ||
| Release gap | Devstral Small shipped 117 days before GPT-5-Codex | |
Which is better: Devstral Small or GPT-5-Codex?
Devstral Small and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Devstral Small shipped 117 days before GPT-5-Codex, so benchmark comparisons should account for the intervening progress.
Devstral Small is open weight, while GPT-5-Codex is proprietary.
Direct benchmark comparisons are unavailable — Devstral Small and GPT-5-Codex don't publish scores on any of the same benchmarks.
Frequently asked questions
Devstral Small was released by Mistral on May 21 2025.
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Devstral Small is an open weight model released by Mistral. GPT-5-Codex is a proprietary model released by OpenAI.
Other comparisons
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