Step 5 Preview scores 54.9 on the Respan Index (#12), ahead of GPT-5.5 at 52.5 (#15). GPT-5.5 leads on 3 of the 3 benchmarks both report. Step 5 Preview is 7.9x cheaper per token at list price.
| Benchmark | GPT-5.5 | Step 5 Preview |
|---|---|---|
| LMArena Agent (LMArena) | 0.0415 | 0.0048 |
| LMArena Elo | 1466 | 1454 |
| LMArena Vision (LMArena) | 1287 | 1260 |
Higher is better. Each score links to where it was published.
* Estimated: no published scores in that category. How the Respan Index works