Claude Sonnet 5.5 scores 68.5 on the Respan Index (#6), ahead of Claude Opus 5 at 63.9 (#7). Claude Sonnet 5.5 leads on 17 of the 23 benchmarks both report. Claude Sonnet 5.5 is 2.5x cheaper per token at list price.
* Estimated: no published scores in that category. How the Respan Index works
| Furniture Assembly (Epoch AI) |
| 60.8% |
| 75% |
| GPQA Diamond | 93.9% | 95.6% |
| LiveBench Agentic Coding (LiveBench) | 65.2% | 56.3% |
| LiveBench Coding (LiveBench) | 81.4% | 91.4% |
| LiveBench Data Analysis (LiveBench) | 74.6% | 78.6% |
| LiveBench Instruction Following (LiveBench) | 63.8% | 70.5% |
| LiveBench Language (LiveBench) | 88.7% | 83.4% |
| LiveBench Mathematics (LiveBench) | 95.7% | 96.7% |
| LiveBench Reasoning (LiveBench) | 91.2% | 91.6% |
| Mystery Game Puzzles (Epoch AI) | 59% | 65% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 98.9% | 100% |
| SAGE (Vals AI) | 49.4% | 51.8% |
| SimpleQA Verified | 59.9% | 46.5% |
| Terminal-Bench 4.0 (Vals AI) | 53.5% | 64.1% |
| LMArena Agent (LMArena) | 0.0867 | 0.1252 |
| LMArena Elo | 1490 | 1471 |
| LMArena Vision (LMArena) | 1289 | 1268 |
| LMArena WebDev (LMArena) | 1695 | 1786 |
| SimpleBench (SimpleBench) | 80.6% | 75.9% |
Higher is better. Each score links to where it was published.