Claude 3 HaikuvsClaude Sonnet 4.5
Claude 3 Haiku | Claude Sonnet 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. | 10% | 79%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. | — | 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. | 33.3% | 83.4%Best |
Multimodal MMMUTests the AI on understanding images and text together across many college subjects. Higher is better. | — | 68% |
| Overview | ||
| Company | Anthropic | Anthropic |
| Release date | Mar 4 2024 | Sep 29 2025 |
| Access | Proprietary | Proprietary |
Which is better: Claude 3 Haiku or Claude Sonnet 4.5?
Claude Sonnet 4.5 leads Claude 3 Haiku on 2 of the 2 benchmarks they both report (BullshitBench v2, GPQA Diamond). Claude 3 Haiku shipped 574 days before Claude Sonnet 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 Sonnet 4.5 leads at 79% vs Claude 3 Haiku at 10%. On GPQA Diamond, Claude Sonnet 4.5 leads at 83.4% vs Claude 3 Haiku at 33.3%.
Frequently asked questions
Claude 3 Haiku was released by Anthropic on Mar 4 2024.
Claude Sonnet 4.5 was released by Anthropic on Sep 29 2025.
Claude Sonnet 4.5 leads on GPQA Diamond — Claude 3 Haiku 33.3% vs Claude Sonnet 4.5 83.4%.
Other comparisons
Claude 3 HaikuvsGPT-5.6 SolClaude Sonnet 4.5vsGPT-5.6 SolClaude 3 HaikuvsGemini 3.6 FlashClaude Sonnet 4.5vsGemini 3.6 FlashClaude 3 HaikuvsMuse GlimmerClaude Sonnet 4.5vsMuse GlimmerClaude 3 HaikuvsGrok 4.5Claude Sonnet 4.5vsGrok 4.5Claude 3 HaikuvsDeepSeek-V4-Flash-0731Claude Sonnet 4.5vsDeepSeek-V4-Flash-0731Claude 3 HaikuvsMistral Medium 3.5Claude Sonnet 4.5vsMistral Medium 3.5