GPT-5.3-CodexvsGrok 4.1 Fast
GPT-5.3-Codex | Grok 4.1 Fast | |
|---|---|---|
| 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. | 24%Best | 19% |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | 83% | — |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | 1406 | — |
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Feb 5 2026 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Which is better: GPT-5.3-Codex or Grok 4.1 Fast?
GPT-5.3-Codex leads Grok 4.1 Fast on 1 of the 1 benchmark they both report (BullshitBench v2). Grok 4.1 Fast shipped 78 days before GPT-5.3-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.
On BullshitBench v2, GPT-5.3-Codex leads at 24% vs Grok 4.1 Fast at 19%.
Frequently asked questions
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
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