Claude Sonnet 5
ECI#31
157Claude Sonnet 5 is a closed-weights model from Anthropic, released June 30, 2026. It has an ECI score of 157 and ranks 31st of 237 tracked models. At the time of its release, it ranked 9th of 196 tracked models.
Claude Sonnet 5 vs select alternatives
| Domain | Benchmark | Claude Sonnet 5 | |||
|---|---|---|---|---|---|
ECI scoreBest score 169 | 157 | 156 | 158 | 157 | |
| Ranking | #31 | #34 | #26 | #30 | |
| Conceptual reasoning | SimpleBenchBest score 82% | ||||
| Games | Chess PuzzlesBest score 76% | ||||
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% | |||||
| Science | GPQA DiamondBest score 96% | ||||
| Software engineering | Text Arena (Coding)Best score 1820 | 1537 | 1556 | 1567 | 1519 |
| World knowledge | SimpleQA VerifiedBest score 76% |
