Claude Opus 5.5 vs Claude Sonnet 5.5
Both are SOTA right now. Each row is one board’s call, and the marked figure is the one that board places higher. No row is added to another, so there is no overall winner: the boards measure different things, and where they split, that is the finding.Each rank is the board’s own: the rank it publishes, or the model’s place in the board’s own order where it publishes none. Scores from different boards cannot be compared.
| Board | Claude Opus 5.5 | Claude Sonnet 5.5 |
|---|---|---|
| Artificial Analysis LLM Leaderboard Artificial Analysis Intelligence Index | 57.6 No. 1 of 375 | 56.0 No. 2 of 375 |
| Arena — Agent Overall | 0.143 No. 1 of 52 | 0.120 No. 4 of 52 |
| Artificial Analysis Coding Agents Artificial Analysis Coding Agent Index | 0.660 No. 2 of 24 | 0.684 No. 1 of 24 |
| Epoch AI Benchmarking Hub FrontierMath Tiers 1–3 | 91.2% No. 3 of 82 | 88.8% No. 7 of 82 |
| Terminal-Bench 4.0 Terminal-Bench 4.0 | 64.8% No. 1 of 35 | 61.8% No. 2 of 35 |
| Arena — Code Overall | 1813 No. 1 of 142 | 1774 No. 3 of 142 |
| Arena — Text Overall (style control) | 1507 No. 2 of 414 | 1476 No. 32 of 414 |
| Arena — Vision Overall (style control) | 1293 No. 11 of 165 | 1266 No. 39 of 165 |
At a glance
| Developer | Anthropic | Anthropic |
|---|---|---|
| Weights | closed | closed |
| Released | — | — |
| Price Blended Price, USD per 1M tokens (3:1 input:output) | $8.00 | $4.00 |
| Value: where it sits on the kill line | SOTA | SOTA |
Claude Opus 5.5 →Claude Sonnet 5.5 → How the kill line is drawn →