Claude Sonnet 4 vs o3
Anthropic Claude Sonnet 4 | OpenAI o3 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | May 22 2025 | Apr 16 2025 |
| Access | Proprietary | Proprietary |
| 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. | 30%Best | 26% |
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. | 72.7% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 75.4% | — |
| Timeline | ||
| Release gap | o3 shipped 36 days before Claude Sonnet 4 | |
Which is better: Claude Sonnet 4 or o3?
Claude Sonnet 4 leads o3 on 1 of the 1 benchmark they both report (BullshitBench v2). o3 shipped 36 days before Claude Sonnet 4, 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 o3 at 26%.
Frequently asked questions
Claude Sonnet 4 was released by Anthropic on May 22 2025.
o3 was released by OpenAI on Apr 16 2025.
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