Claude 3.5 SonnetvsClaude Opus 4.5
Claude 3.5 Sonnet | Claude Opus 4.5 | |
|---|---|---|
| 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. | 45% | 90%Best |
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. | 33.4% | 80.9%Best |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 59.4% | 87%Best |
| Overview | ||
| Company | Anthropic | Anthropic |
| Release date | Jun 20 2024 | Nov 24 2025 |
| Access | Proprietary | Proprietary |
Which is better: Claude 3.5 Sonnet or Claude Opus 4.5?
Claude Opus 4.5 leads Claude 3.5 Sonnet on 3 of the 3 benchmarks they both report (BullshitBench v2, SWE-Bench Verified, GPQA Diamond). Claude 3.5 Sonnet shipped 522 days before Claude Opus 4.5, 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 4.5 leads at 90% vs Claude 3.5 Sonnet at 45%. On SWE-Bench Verified, Claude Opus 4.5 leads at 80.9% vs Claude 3.5 Sonnet at 33.4%. On GPQA Diamond, Claude Opus 4.5 leads at 87% vs Claude 3.5 Sonnet at 59.4%.
Frequently asked questions
Claude 3.5 Sonnet was released by Anthropic on Jun 20 2024.
Claude Opus 4.5 was released by Anthropic on Nov 24 2025.
Claude Opus 4.5 leads on SWE-Bench Verified — Claude 3.5 Sonnet 33.4% vs Claude Opus 4.5 80.9%.
Claude Opus 4.5 leads on GPQA Diamond — Claude 3.5 Sonnet 59.4% vs Claude Opus 4.5 87%.