Claude Haiku 5.5
ECI#17
159Claude Haiku 5.5 is a closed-weights model from Anthropic, released October 7, 2026. It has an ECI score of 159 and ranks 17th of 256 tracked models. At the time of its release, it ranked 15th of 252 tracked models.
Claude Haiku 5.5 vs select alternatives
| Domain | Benchmark | Claude Haiku 5.5 | |||
|---|---|---|---|---|---|
ECI scoreBest score 169 | 159 | 159 | 163 | 159 | |
| Ranking | #17 | #18 | #10 | #19 | |
| Games | Chess PuzzlesBest score 76% | ||||
Earthborne Rangers (EBR-bench)Best score 78% | |||||
Mystery Game PuzzlesBest score 84% | |||||
| Mathematics | FrontierMath Tiers 1-3 (v2)Best score 94% | ||||
FrontierMath Tier 4 (v2)Best score 100% | |||||
OTIS Mock AIME 2024-2025Best score 100% | |||||
| Multimodal | Furniture Assembly BenchmarkBest score 83% | ||||
| Science | GPQA DiamondBest score 96% | ||||
| World knowledge | SimpleQA VerifiedBest score 76% |
