Claude Sonnet 5.5 scores 68.5 on the Respan Index (#6), ahead of Claude Fable 5 at 62.2 (#9). Claude Sonnet 5.5 leads on 12 of the 23 benchmarks both report. Claude Sonnet 5.5 is 5.0x cheaper per token at list price.
* Estimated: no published scores in that category. How the Respan Index works
| Furniture Assembly (Epoch AI) | 35.8% | 75% |
| GPQA Diamond | 85.9% | 95.6% |
| LiveBench Agentic Coding (LiveBench) | 62.2% | 56.3% |
| LiveBench Coding (LiveBench) | 86% | 91.4% |
| LiveBench Data Analysis (LiveBench) | 80.5% | 78.6% |
| LiveBench Instruction Following (LiveBench) | 75.8% | 70.5% |
| LiveBench Language (LiveBench) | 90.7% | 83.4% |
| LiveBench Mathematics (LiveBench) | 96% | 96.7% |
| LiveBench Reasoning (LiveBench) | 89.7% | 91.6% |
| Mystery Game Puzzles (Epoch AI) | 52% | 65% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 100% | 100% |
| SAGE (Vals AI) | 51.9% | 51.8% |
| SimpleQA Verified | 70.7% | 46.5% |
| Terminal-Bench 4.0 (Vals AI) | 41.4% | 64.1% |
| LMArena Agent (LMArena) | 0.0821 | 0.1252 |
| LMArena Elo | 1504 | 1471 |
| LMArena Vision (LMArena) | 1309 | 1268 |
| LMArena WebDev (LMArena) | 1625 | 1786 |
| SimpleBench (SimpleBench) | 81.9% | 75.9% |
Higher is better. Each score links to where it was published.