Claude Opus 4.5
ECI#61
152Claude Opus 4.5 is a closed-weights model from Anthropic, released November 24, 2025. It has an ECI score of 152 and ranks 61st of 240 tracked models. At the time of its release, it ranked 2nd of 148 tracked models.
Claude Opus 4.5 vs select alternatives
| Domain | Benchmark | Claude Opus 4.5 | |||
|---|---|---|---|---|---|
ECI scoreBest score 173 | 152 | 148 | 153 | 151 | |
| Ranking | #61 | #80 | #55 | #63 | |
| Games | Chess PuzzlesBest score 79% | ||||
Mystery Game PuzzlesBest score 90% | |||||
Earthborne Rangers (EBR-bench)Best score 90% | |||||
| Mathematics | FrontierMath Tiers 1-3 (v2)Best score 95% | ||||
FrontierMath Tier 4 (v2)Best score 100% | |||||
OTIS Mock AIME 2024-2025Best score 100% | |||||
| Science | GPQA DiamondBest score 97% | ||||
| Software engineering | SWE-bench VerifiedBest score 83% | ||||
| World knowledge | SimpleQA VerifiedBest score 94% |
