GPT-5-CodexvsGrok 4.1 Fast
GPT-5-Codex | Grok 4.1 Fast | |
|---|---|---|
| Benchmarks | ||
BullshitBench v2Nonsense detection — Given 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% | 19% |
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Sep 15 2025 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Other comparisons
GPT-5-CodexvsClaude Fable 5.1Grok 4.1 FastvsClaude Fable 5.1GPT-5-CodexvsGemini 3.8 FlashGrok 4.1 FastvsGemini 3.8 FlashGPT-5-CodexvsMuse Spark 1.3Grok 4.1 FastvsMuse Spark 1.3GPT-5-CodexvsDeepSeek-V4.1-FlashGrok 4.1 FastvsDeepSeek-V4.1-FlashGPT-5-CodexvsMistral Medium 3.5Grok 4.1 FastvsMistral Medium 3.5GPT-5-CodexvsKimi K3Grok 4.1 FastvsKimi K3
Frequently asked questions
GPT-5-Codex leads Grok 4.1 Fast on 1 of the 1 benchmark they both report (BullshitBench v2). GPT-5-Codex shipped 65 days before Grok 4.1 Fast, 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.
On BullshitBench v2, GPT-5-Codex leads at 39% vs Grok 4.1 Fast at 19%.