Claude Sonnet 5 launches at $2 per million tokens

Anthropic launched Claude Sonnet 5 on 30 June 2026, calling it its most agentic Sonnet yet — a model built to plan, use tools like browsers and terminals, and run autonomously at a level that months ago needed larger, pricier models. The API name is claude-sonnet-5. It is available on every plan and is now the default model for Free and Pro users, as well as Max, Team and Enterprise.

On performance, Anthropic says Sonnet 5 approaches Opus 4.8 for less money. It scored 63.2% on an agentic coding benchmark (Opus 4.8: 69.2%; Sonnet 4.6: 58.1%) and slightly outperforms Opus 4.8 on a knowledge-work benchmark. An adjustable effort level lets developers trade cost against performance.

Pricing is the headline. Introductory rates run through 31 August 2026, then step up to standard.

Sonnet 5 shows a lower overall rate of undesirable behaviours than Sonnet 4.6 and is safer in agentic use. Notably, Anthropic made an explicit decision not to train it on cybersecurity tasks, leaving it substantially weaker at exploit development than Opus 4.8 — a pointed choice in the same month the US pulled Fable 5 and Mythos 5 over cyber capability.