Claude Opus 4.6 is Anthropic's most intelligent model, upgrading its predecessor's coding, reasoning, and agentic capabilities. It plans more carefully, sustains agentic tasks for longer, operates more reliably in larger codebases, and has superior code review and debugging skills. In a first for Opus-class models, it features a 1M token context window (beta) and 128K max output tokens. Opus 4.6 achieves state-of-the-art results on Terminal-Bench 2.0 (65.4%), leads on Humanity's Last Exam, BrowseComp, and GDPval-AA, and scores 76% on the 8-needle 1M variant of MRCR v2 (vs. 18.5% for Sonnet 4.5), representing a qualitative leap in long-context performance. It introduces adaptive thinking and four effort levels (low, medium, high, max) for fine-grained control over intelligence, speed, and cost.
Typemultimodal
ParametersUnreleased