Claude app release notes·· 2026-09-28
Claude Sonnet 5.5 launch
Claude Sonnet 5.5 launch
Brief overview
Anthropic releases Claude Sonnet 5.5, the second model in the Claude 5.5 family, as a faster and more affordable supplement to Claude Opus 5.5.
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Claude Sonnet 5.5 launch
We just launched Claude Sonnet 5.5, the second model in our Claude 5.5 family. Sonnet 5.5 is a faster, lower-cost complement to Claude Opus 5.5. For more information, see our blog post: Introducing Claude Sonnet 5.5.
Source: Claude app release notes · support.claude.com