Claude Haiku 4.5 vs o3
Anthropic Claude Haiku 4.5 | OpenAI o3 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | OpenAI |
| Release date | Oct 15 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. | 77%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. | 73.3% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 73% | — |
| Timeline | ||
| Release gap | o3 shipped 182 days before Claude Haiku 4.5 | |
Which is better: Claude Haiku 4.5 or o3?
Claude Haiku 4.5 leads o3 on 1 of the 1 benchmark they both report (BullshitBench v2). o3 shipped 182 days before Claude Haiku 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 Haiku 4.5 leads at 77% vs o3 at 26%.
Frequently asked questions
Claude Haiku 4.5 was released by Anthropic on Oct 15 2025.
o3 was released by OpenAI on Apr 16 2025.
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