Anthropic Launches Claude 4 with Opus & Sonnet

Anthropic has launched Claude 4, introducing the Sonnet 4 and Opus 4 models after a year-long pause. Aimed at the emerging “agentic era,” Opus 4 can handle multi-hour tasks autonomously—successfully completing a seven-hour coding project in tests. It outperformed GPT-4.1 and Gemini 2.5 Pro in software engineering benchmarks. Claude 4 also experiments with extended reasoning using tools like web search. The Claude Code assistant is now publicly available; Sonnet 4 is free to use online, while Opus 4 remains part of the paid tier. API pricing for developers stays the same.