Claude Opus 4.8
ECI#12
158Claude Opus 4.8 is a closed-weights model from Anthropic, released May 28, 2026. It has an ECI score of 158 and ranks 12th of 253 tracked models. At the time of its release, it ranked 4th of 217 tracked models.
Claude Opus 4.8 vs select alternatives
| Domain | Benchmark | Claude Opus 4.8 | |||
|---|---|---|---|---|---|
ECI scoreBest score 167 | 158 | 156 | 162 | 155 | |
| Ranking | #12 | #22 | #6 | #31 | |
| Games | Chess PuzzlesBest score 72% | ||||
Earthborne Rangers (EBR-bench)Best 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% | |||||
| Multimodal | Furniture Assembly BenchmarkBest score 83% | ||||
| Science | GPQA DiamondBest score 96% | ||||
| World knowledge | SimpleQA VerifiedBest score 76% |
