Compare / Claude Opus 5 vs Claude Sonnet 5.5
Claude Opus 5 vs Claude Sonnet 5.5
7 results from 3 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Opus 5 | Claude Sonnet 5.5 |
|---|---|---|---|
| APEX-Agentsreported | Tasks passed% of tasks | 65.8% | 75.5% |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 50.8 | 56.0 |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 54.9% | 55.0% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 82.0% | 82.7% |
| Artificial Analysisreported | SciCode% of problems | 56.4% | 61.0% |
| Artificial Analysisreported | Terminal-Bench 4.0% of tasks | 49.0% | 63.6% |
| SimpleQA Verified (Epoch AI)reported | Correct answers% of questions | 59.9% | 46.5% |
Bold green marks the better value on that metric. Where a source reports ranges that overlap, the difference may not be meaningful; see the benchmark page for ranges.