Claude Opus 5.5 scores 72.4 on the Respan Index (#1), ahead of Gemini 4 Argon at 70.3 (#3). They split the 8 benchmarks both report evenly. Gemini 4 Argon is 2.0x cheaper per token at list price.
* Estimated: no published scores in that category. How the Respan Index works
| 9235.25 |
| 13718.16 |
| LMArena Agent (LMArena) | 0.1382 | 0.0757 |
| LMArena Elo | 1504 | 1525 |
| LMArena WebDev (LMArena) | 1815 | 1680 |
Higher is better. Each score links to where it was published.