Claude Opus 5.5 scores 72.4 on the Respan Index (#1), ahead of Claude Opus 5 at 63.9 (#7). Claude Opus 5.5 leads on 21 of the 25 benchmarks both report. Claude Opus 5.5 is 1.3x cheaper per token at list price.
* Estimated: no published scores in that category. How the Respan Index works
| FrontierSWE V2 (Proximal Labs) |
| 52% |
| 62.3% |
| Furniture Assembly (Epoch AI) | 60.8% | 83.3% |
| GPQA Diamond | 93.9% | 90.6% |
| LiveBench Agentic Coding (LiveBench) | 65.2% | 71.7% |
| LiveBench Coding (LiveBench) | 81.4% | 89.3% |
| LiveBench Data Analysis (LiveBench) | 74.6% | 80.3% |
| LiveBench Instruction Following (LiveBench) | 63.8% | 67% |
| LiveBench Language (LiveBench) | 88.7% | 86.3% |
| LiveBench Mathematics (LiveBench) | 95.7% | 97.1% |
| LiveBench Reasoning (LiveBench) | 91.2% | 92.2% |
| Mystery Game Puzzles (Epoch AI) | 59% | 71% |
| OTIS Mock AIME 2024-2025 (Epoch AI) | 98.9% | 100% |
| SAGE (Vals AI) | 49.4% | 45.8% |
| SimpleQA Verified | 59.9% | 72.2% |
| Terminal-Bench 4.0 (Vals AI) | 53.5% | 65.2% |
| Vending-Bench 2 (Andon Labs) | 11181.87 | 9235.25 |
| LMArena Agent (LMArena) | 0.0867 | 0.1382 |
| LMArena Elo | 1490 | 1504 |
| LMArena WebDev (LMArena) | 1695 | 1815 |
| Terminal-Bench Science 0.1 | 29% | 58.7% |
| SimpleBench (SimpleBench) | 80.6% | 88.4% |
Higher is better. Each score links to where it was published.