o4-minivsGrok 4.1 Fast
o4-mini | 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. | 8% | 19%Best |
| Overview | ||
| Company | OpenAI | SpaceXAI |
| Release date | Apr 16 2025 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Which is better: o4-mini or Grok 4.1 Fast?
Grok 4.1 Fast leads o4-mini on 1 of the 1 benchmark they both report (BullshitBench v2). o4-mini shipped 217 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 o4-mini at 8%.
Frequently asked questions
o4-mini was released by OpenAI on Apr 16 2025.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
Other comparisons
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