Claude Sonnet 4vsGrok 4.1 Fast
Claude Sonnet 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. | 30% | 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. | 72.7% | — |
GPQA DiamondScience — Graduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4% | — |
| Overview | ||
| Company | Anthropic | SpaceXAI |
| Release date | May 22 2025 | Nov 19 2025 |
| Access | Proprietary | Proprietary |
Frequently asked questions
Claude Sonnet 4 leads Grok 4.1 Fast on 1 of the 1 benchmark they both report (BullshitBench v2). Claude Sonnet 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 Sonnet 4 leads at 30% vs Grok 4.1 Fast at 19%.
Claude Sonnet 4 was released by Anthropic on May 22 2025.
Grok 4.1 Fast was released by SpaceXAI on Nov 19 2025.
Other comparisons
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