Compare / Claude Opus 4.6 vs Claude Opus 5.5
Claude Opus 4.6 vs Claude Opus 5.5
14 results from 5 sources that measured both models. Each row is in the source's own units; there is no overall winner.
| Benchmark | Metric | Claude Opus 4.6 | Claude Opus 5.5 |
|---|---|---|---|
| APEX-Agentsreported | Tasks passed% of tasks | 46.3% | 73.5% |
| Arena (formerly LMArena)reported | Business, management and financeArena rating | 1,501 | 1,499 |
| Arena (formerly LMArena)reported | Creative writingArena rating | 1,501 | 1,521 |
| Arena (formerly LMArena)reported | Expert promptsArena rating | 1,547 | 1,556 |
| Arena (formerly LMArena)reported | Instruction followingArena rating | 1,513 | 1,516 |
| Arena (formerly LMArena)reported | OverallArena rating | 1,505 | 1,509 |
| Arena (formerly LMArena)reported | Writing, literature and languageArena rating | 1,500 | 1,520 |
| Artificial Analysisreported | Artificial Analysis Intelligence Indexindex score | 31.9 | 57.6 |
| Artificial Analysisreported | Humanity's Last Exam% of questions | 39.9% | 61.4% |
| Artificial Analysisreported | Long-context reasoning (AA-LCR)% of questions | 78.0% | 84.7% |
| SimpleQA Verified (Epoch AI)reported | Correct answers% of questions | 47.0% | 72.2% |
| UGI Leaderboardreported | Requested-length error% off the requested word count | 3.0% | 2.0% |
| UGI Leaderboardreported | Style adherencescore from 0 to 1 | 0.41 | 0.43 |
| UGI Leaderboardreported | Writing scorescore out of 100 | 70.9 | 70.0 |
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.