Claude 3.5 Sonnet (upgraded) vs Claude Opus 4
Anthropic Claude 3.5 Sonnet (upgraded) | Anthropic Claude Opus 4 | |
|---|---|---|
| Overview | ||
| Company | Anthropic | Anthropic |
| Release date | Oct 22 2024 | May 22 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. | — | 34% |
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. | 49% | 72.5%Best |
Science GPQA DiamondGraduate-level science questions in biology, physics, and chemistry — hard enough that subject-matter PhDs score around 65%. Higher is better. | — | 79.6% |
| Timeline | ||
| Release gap | Claude 3.5 Sonnet (upgraded) shipped 212 days before Claude Opus 4 | |
Which is better: Claude 3.5 Sonnet (upgraded) or Claude Opus 4?
Claude Opus 4 leads Claude 3.5 Sonnet (upgraded) on 1 of the 1 benchmark they both report (SWE-Bench Verified). Claude 3.5 Sonnet (upgraded) shipped 212 days before Claude Opus 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 SWE-Bench Verified, Claude Opus 4 leads at 72.5% vs Claude 3.5 Sonnet (upgraded) at 49%.
Frequently asked questions
Claude 3.5 Sonnet (upgraded) was released by Anthropic on Oct 22 2024.
Claude Opus 4 was released by Anthropic on May 22 2025.
Claude Opus 4 leads on SWE-Bench Verified — Claude 3.5 Sonnet (upgraded) 49% vs Claude Opus 4 72.5%.
Other comparisons
Claude 3.5 Sonnet (upgraded) vs GPT-5.6 SolClaude Opus 4 vs GPT-5.6 SolClaude 3.5 Sonnet (upgraded) vs Gemini OmniClaude Opus 4 vs Gemini OmniClaude 3.5 Sonnet (upgraded) vs Muse Spark 1.1Claude Opus 4 vs Muse Spark 1.1Claude 3.5 Sonnet (upgraded) vs Grok 4.5Claude Opus 4 vs Grok 4.5Claude 3.5 Sonnet (upgraded) vs DeepSeek-V4-ProClaude Opus 4 vs DeepSeek-V4-ProClaude 3.5 Sonnet (upgraded) vs Mistral Medium 3.5Claude Opus 4 vs Mistral Medium 3.5