Compare / Claude Opus 5.5 vs GPT-5 Nano
Claude Opus 5.5 vs GPT-5 Nano
10 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 5.5 | GPT-5 Nano |
|---|---|---|---|
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,499 | 1,339 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,521 | 1,247 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,556 | 1,354 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,516 | 1,327 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,509 | 1,338 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,520 | 1,289 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 57.6 | 13.0 |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 61.4% | 9.5% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 84.7% | 45.0% |
| SimpleQA Verified (Epoch AI)reported | Correct answers% of questions | 72.2% | 11.7% |
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.