Claude Opus 4vsGrok 4.1 Fast
Claude Opus 4 | 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. | 34% | 19% |
| BenchmarksPublished by one model only | ||
SWE-Bench VerifiedCoding — Real coding tasks pulled from open-source projects — the AI has to find and fix actual bugs. A human-checked version of the original SWE-Bench. Higher is better. | 72.5% | — |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 79.6% | — |
| Overview | ||
| Company | Anthropic | SpaceXAI |
| Release date | May 22 2025 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Frequently asked questions
Claude Opus 4 leads Grok 4.1 Fast on 1 of the 1 benchmark they both report (BullshitBench v2). Claude Opus 4 shipped 181 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, Claude Opus 4 leads at 34% vs Grok 4.1 Fast at 19%.
Claude Opus 4 was released by Anthropic on May 22 2025.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
Other comparisons
Claude Opus 4vsGPT-5.6-CyberGrok 4.1 FastvsGPT-5.6-CyberClaude Opus 4vsGemini 3.7 FlashGrok 4.1 FastvsGemini 3.7 FlashClaude Opus 4vsMuse GlimmerGrok 4.1 FastvsMuse GlimmerClaude Opus 4vsDeepSeek-V4-Pro-0813Grok 4.1 FastvsDeepSeek-V4-Pro-0813Claude Opus 4vsMistral Medium 3.5Grok 4.1 FastvsMistral Medium 3.5Claude Opus 4vsKimi K3Grok 4.1 FastvsKimi K3