GPT-4ovsGrok 4.1 Fast
GPT-4o | Grok 4.1 Fast | |
|---|---|---|
| Specifications | ||
Context window | 128k | — |
| 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. | 12% | 19%Best |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 49.9% | — |
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | May 13 2024 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Which is better: GPT-4o or Grok 4.1 Fast?
Grok 4.1 Fast leads GPT-4o on 1 of the 1 benchmark they both report (BullshitBench v2). GPT-4o shipped 555 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, Grok 4.1 Fast leads at 19% vs GPT-4o at 12%.
Frequently asked questions
GPT-4o was released by OpenAI on May 13 2024.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
Other comparisons
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