Claude Opus 5 scores 63.9 on the Respan Index (#7), ahead of Step 5 Preview at 54.9 (#12). Claude Opus 5 leads on 5 of the 5 benchmarks both report. Step 5 Preview is 7.0x cheaper per token at list price.
* Estimated: no published scores in that category. How the Respan Index works
| LMArena WebDev (LMArena) |
| 1695 |
| 1570 |
Higher is better. Each score links to where it was published.