Claude Opus 4.5

Health summary

19 of 26 scores sit on benchmarks that still discriminate. Every number here has been measured independently. 17 sit on benchmarks with a high risk of test-set contamination.

Epoch Capability Index

150.2 (147.9–152.8)

Epoch AI's Capability Index. A composite score with no benchmark health record behind it, so it is never this site's ranking basis and is always attributed. Published by Epoch AI under CC BY 4.0. fetched 2026-10-19

Scores