Anthropic launches Claude Sonnet 5.5: 30%+ faster, up to 30% cheaper for most work

claudeai · x · 2026-09-29

Anthropic officially announces Claude Sonnet 5.5, the second model in the Claude 5.5 family. The company calls it a clear upgrade over Sonnet 5: it runs more than 30% faster and costs up to 30% less for most work. Claude Haiku 5.5, aimed at high-volume, cost-sensitive applications, will join the family in the coming weeks.

Related event: Anthropic Launches Claude Sonnet 5.5: 30% Faster, Up to 30% Cheaper(30 posts)→

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