Claude Sonnet 4.5 vs Gemini 3.1 Flash
Anthropic Claude Sonnet 4.5 | Google Gemini 3.1 Flash | |
|---|---|---|
| Overview | ||
| Company | Anthropic | |
| Release date | Sep 29 2025 | Feb 26 2026 |
| 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. | 79% | — |
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. | 77.2% | — |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | 50% | — |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | 83.4% | — |
Multimodal MMMUTests the AI on understanding images and text together across many college subjects. Higher is better. | 68% | — |
| Timeline | ||
| Release gap | Claude Sonnet 4.5 shipped 150 days before Gemini 3.1 Flash | |
Which is better: Claude Sonnet 4.5 or Gemini 3.1 Flash?
Claude Sonnet 4.5 and Gemini 3.1 Flash don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Claude Sonnet 4.5 shipped 150 days before Gemini 3.1 Flash, 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.
Direct benchmark comparisons are unavailable — Claude Sonnet 4.5 and Gemini 3.1 Flash don't publish scores on any of the same benchmarks.
Frequently asked questions
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
Gemini 3.1 Flash was released by Google on Feb 26 2026.
Other comparisons
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