OpenAI GPT-5.1-Codex-Max vs xAI Grok Code Fast 1 — side-by-side specs.
OpenAI GPT-5.1-Codex-Max | xAI Grok Code Fast 1 | |
|---|---|---|
| Overview | ||
| Company | OpenAI | xAI |
| Release date | Nov 19 2025 | Aug 28 2025 |
| Model type | — | — |
| Open source | No | No |
| Specifications | ||
Parameters | — | — |
Context window | — | — |
| Benchmarks | ||
| Timeline | ||
| Release gap | Grok Code Fast 1 shipped 83 days before GPT-5.1-Codex-Max | |
GPT-5.1-Codex-Max and Grok Code Fast 1 don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Grok Code Fast 1 shipped 83 days before GPT-5.1-Codex-Max, so benchmark comparisons should account for the intervening progress.
Published specifications for these two models are limited — see each model page for the latest details.
Direct benchmark comparisons are unavailable — GPT-5.1-Codex-Max and Grok Code Fast 1 don't publish scores on any of the same benchmarks.