Claude Opus 4.5 vs Gemini 2.5 Flash
Anthropic Claude Opus 4.5 | Google Gemini 2.5 Flash | |
|---|---|---|
| Overview | ||
| Company | Anthropic | |
| Release date | Nov 24 2025 | Apr 17 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. | 90%Best | 19% |
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. | 80.9% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 87% | — |
| Timeline | ||
| Release gap | Gemini 2.5 Flash shipped 221 days before Claude Opus 4.5 | |
Which is better: Claude Opus 4.5 or Gemini 2.5 Flash?
Claude Opus 4.5 leads Gemini 2.5 Flash on 1 of the 1 benchmark they both report (BullshitBench v2). Gemini 2.5 Flash shipped 221 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 Gemini 2.5 Flash at 19%.
Frequently asked questions
Claude Opus 4.5 was released by Anthropic on Nov 24 2025.
Gemini 2.5 Flash was released by Google on Apr 17 2025.
Other comparisons
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