GPT-5-Codex vs Grok Code Fast 1
OpenAI GPT-5-Codex | SpaceXAI Grok Code Fast 1 | |
|---|---|---|
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Sep 15 2025 | Aug 28 2025 |
| Access | Proprietary | Proprietary |
| 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 | Grok Code Fast 1 shipped 18 days before GPT-5-Codex | |
Which is better: GPT-5-Codex or Grok Code Fast 1?
GPT-5-Codex 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 18 days before GPT-5-Codex, 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-Codex and Grok Code Fast 1 don't publish scores on any of the same benchmarks.
Frequently asked questions
GPT-5-Codex was released by OpenAI on Sep 15 2025.
Grok Code Fast 1 was released by SpaceXAI on Aug 28 2025.
Other comparisons
GPT-5-Codex vs Claude Sonnet 5Grok Code Fast 1 vs Claude Sonnet 5GPT-5-Codex vs Gemini OmniGrok Code Fast 1 vs Gemini OmniGPT-5-Codex vs Muse Spark 1.1Grok Code Fast 1 vs Muse Spark 1.1GPT-5-Codex vs DeepSeek-V4-ProGrok Code Fast 1 vs DeepSeek-V4-ProGPT-5-Codex vs Mistral Medium 3.5Grok Code Fast 1 vs Mistral Medium 3.5GPT-5-Codex vs Kimi K2.7 CodeGrok Code Fast 1 vs Kimi K2.7 Code