Anthropic launches Claude Sonnet 5 with near-Opus agentic performance at lower cost for developers and Claude users

Anthropic introduced Claude Sonnet 5, positioning it as its most agentic Sonnet model yet, with stronger reasoning, coding, tool use, and autonomous task execution than Sonnet 4.6. The model is now the default for Free and Pro Claude plans, available across paid tiers, Claude Code, and the Claude API with introductory pricing through August 31, 2026.

Sonnet 5 reflects a broader push to bring agentic AI capabilities down from premium frontier models into cheaper, mainstream tiers. If its near-Opus performance holds up in real-world use, it could accelerate adoption of AI coding agents and autonomous workplace tools while increasing pricing pressure across the model market.