Claude 4

Major generation leap with Opus and Sonnet variants. Claude 4 Sonnet introduced 1M token context. Both models achieved record SWE-bench Verified scores: Opus 72.5%, Sonnet 72.7%. Architecture undisclosed.

Claude 4 was widely regarded as the best coding model at launch, with particular strength in agentic tasks, extended reasoning, and instruction following. Launched alongside Claude Code GA and the Claude Agent SDK. AA Intelligence Index: 33 (Opus), 33 (Sonnet). Proprietary.