Claude Haiku 5.5 vs 
Step 5
Both are SOTA right now. Each row is one board’s call, and the marked figure is the one that board places higher. No row is added to another, so there is no overall winner: the boards measure different things, and where they split, that is the finding.Each rank is the board’s own: the rank it publishes, or the model’s place in the board’s own order where it publishes none. Scores from different boards cannot be compared.
| Board | Claude Haiku 5.5 | Step 5 |
|---|---|---|
| Artificial Analysis LLM Leaderboard Artificial Analysis Intelligence Index | 43.4 No. 19 of 375 | 43.7 No. 17 of 375 |
| Arena — Agent Overall | — | 0.000 No. 33 of 52 |
| Artificial Analysis Coding Agents Artificial Analysis Coding Agent Index | 0.414 No. 22 of 24 | 0.512 No. 16 of 24 |
| Epoch AI Benchmarking Hub FrontierMath Tiers 1–3 | 75.1% No. 18 of 82 | — |
| Arena — Code Overall | 1587 No. 30 of 142 | 1564 No. 35 of 142 |
| Arena — Text Overall (style control) | — | 1447 No. 83 of 414 |
| Arena — Vision Overall (style control) | — | 1250 No. 55 of 165 |
At a glance
| Developer | Anthropic | StepFun |
|---|---|---|
| Weights | closed | closed |
| Released | — | — |
| Price Blended Price, USD per 1M tokens (3:1 input:output) | $0.20 | $1.43 |
| Value: where it sits on the kill line | Executioner | SOTA |
Claude Haiku 5.5 →Step 5 → How the kill line is drawn →