Anthropic released Claude Sonnet 5.5 on September 28, 2026. It is the second model in the Claude 5.5 family.
What to know
- Anthropic says it runs more than 30% faster than Sonnet 5 and costs up to 30% less for most work, because it typically needs fewer tokens for the same task.
- Per-token prices are unchanged from Sonnet 5: $2 per million input tokens and $10 per million output tokens, with $0.20 for cache reads and $2.50 for cache writes.
- It is available on the Claude Platform as
claude-sonnet-5-5and on Amazon Web Services, Google Cloud and Microsoft Azure. - Claude Opus 5.5 is positioned for complex work that needs careful judgment. Claude Haiku 5.5, for high-volume and cost-sensitive use, was announced as launching in the coming weeks.
Update, October 7, 2026: Haiku 5.5 launched, and Anthropic cut Sonnet 5.5 cache-read prices from $0.20 to $0.10 per million tokens. See our Haiku 5.5 summary.
Disclosure: Anthropic’s Claude is one of the tools used to help build this site. We cover Claude models on the same basis as every other maker.
Source: Anthropic. We summarise in our own words; check the source for the full details.