Claude Opus 4.1
ECI#83
144Claude Opus 4.1 is a closed-weights model from Anthropic, released August 5, 2025. It has an ECI score of 144 and ranks 83rd of 249 tracked models. At the time of its release, it ranked 7th of 156 tracked models.
Input price—
Output price—
ParametersUnknown
Training computeUnknown
Claude Opus 4.1 vs select alternatives
Reasoning
| Domain | Benchmark | Claude Opus 4.1 | |||
|---|---|---|---|---|---|
ECI scoreBest score 166 | 144 | 143 | 144 | 145 | |
| Ranking | #83 | #90 | #85 | #76 | |
| Games | Chess PuzzlesBest score 72.0% | ||||
Mystery Game PuzzlesBest score 84.0% | |||||
| Mathematics | FrontierMath Tiers 1-3 (v2)Best score 93.7% | ||||
FrontierMath Tier 4 (v2)Best score 97.6% | |||||
OTIS Mock AIME 2024-2025Best score 100.0% | |||||
| Science | Humanity's Last ExamBest score 46.5% | ||||
GPQA DiamondBest score 95.8% | |||||
| Software engineering | METR Time HorizonsBest score 1044.8 | 113.7 | 100.4 | — | 38.7 |
SWE-bench VerifiedBest score 83.5% |
