Claude Sonnet 4.6
ECI#50
153Claude Sonnet 4.6 is a closed-weights model from Anthropic, released February 17, 2026. It has an ECI score of 153 and ranks 50th of 254 tracked models. At the time of its release, it ranked 5th of 175 tracked models.
Claude Sonnet 4.6 vs select alternatives
| Domain | Benchmark | Claude Sonnet 4.6 | |||
|---|---|---|---|---|---|
ECI scoreBest score 169 | 153 | 156 | 157 | 153 | |
| Ranking | #50 | #36 | #31 | #48 | |
| Conceptual reasoning | ARC-AGI-2Best score 95% | ||||
ARC-AGI-1Best score 99% | |||||
| Games | Chess PuzzlesBest score 76% | ||||
Mystery Game PuzzlesBest score 84% | |||||
| Mathematics | OTIS Mock AIME 2024-2025Best score 100% | ||||
| Science | GPQA DiamondBest score 96% | ||||
| Software engineering | SWE-bench VerifiedBest score 83% | ||||
Terminal-Bench 2.0Best score 85% | |||||
| World knowledge | SimpleQA VerifiedBest score 76% |
