Opus 5.5 cuts base token and cache-read prices

Anthropic introduced Claude Opus 5.5 on 22 September at $4 per million input tokens and $20 per million output tokens, 20% below Opus 5’s base rates. Cache reads were listed at $0.20 per million tokens, a larger reduction. Anthropic said typical tasks at default settings cost around 40% less in its tests.

The difference between a rate reduction and a task-cost reduction matters: cached input and the number of tokens used affect the final bill. The launch also increased five-hour limits on several subscriptions and added a rate-limit reset that users could save. Anthropic reported improved behaviour and prompt-injection resistance, with specialised safeguards around biology and cybersecurity. Those safeguards accompany greater capability rather than certifying every autonomous action as reliable.