Opus 5.5 lands 40% cheaper to run than Opus 5

One early tester finished a 680,000-line code migration in less than a day, work Anthropic says would have taken an engineering team weeks. Claude Opus 5.5 opens the Claude 5.5 family and, per Anthropic, matches Claude Fable 5.1 on most work at 40% lower running cost than Opus 5 at default settings.

Tokens run $4 in and $20 out per million, and cache reads, which carry most of the bill in agentic coding, drop to $0.20, 60% below Opus 5.

Most cybersecurity tasks re-route to Opus 4.8, since Opus 5.5 ships with the same class of cyber and biology safeguards as Fable 5.1. Anthropic also reports signs that the model often suspects it is being evaluated, which challenges its own ability to assess how it will act.

It’s live on AWS, Google Cloud and Azure as claude-opus-5-5, with Sonnet 5.5 and Haiku 5.5 following in the coming weeks.