Claude Opus 4.5, released by Anthropic in November 2025, is Anthropic's top-tier model delivering state-of-the-art performance on complex coding, reasoning, and long-running agentic tasks. It scores highly on coding benchmarks like SWE-bench and is used for large-scale software work and deep analysis.
Last 12 weeks · weekly buckets. New tools get more accurate as observation weeks add up.
Where builders who adopted this model actually run it — distribution by adopters.