Claude 3.5 Sonnet (upgraded)vsClaude Opus 4.1
Claude 3.5 Sonnet (upgraded) | Claude Opus 4.1 | |
|---|---|---|
| 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. | — | 43% |
Coding SWE-Bench VerifiedReal 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. | 49% | 74.5%Best |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 80.9% |
| Overview | ||
| Company | Anthropic | Anthropic |
| Release date | Oct 22 2024 | Aug 5 2025 |
| Access | Proprietary | Proprietary |
Which is better: Claude 3.5 Sonnet (upgraded) or Claude Opus 4.1?
Claude Opus 4.1 leads Claude 3.5 Sonnet (upgraded) on 1 of the 1 benchmark they both report (SWE-Bench Verified). Claude 3.5 Sonnet (upgraded) shipped 287 days before Claude Opus 4.1, 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 SWE-Bench Verified, Claude Opus 4.1 leads at 74.5% vs Claude 3.5 Sonnet (upgraded) at 49%.
Frequently asked questions
Claude 3.5 Sonnet (upgraded) was released by Anthropic on Oct 22 2024.
Claude Opus 4.1 was released by Anthropic on Aug 5 2025.
Claude Opus 4.1 leads on SWE-Bench Verified — Claude 3.5 Sonnet (upgraded) 49% vs Claude Opus 4.1 74.5%.
Other comparisons
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