Sonnet 5.5 is smarter, more efficient, and 30% faster than Sonnet 5. It costs up to 30% less for most work, so your Claude Code usage goes further too.
Use it for well-scoped everyday tasks like fixing bugs and quickly iterating on features.
ClaudeDevs
@ClaudeDevs
Claude @claudeai
Introducing Claude Sonnet 5.5, the second model in the Claude 5.5 family.
It’s a clear upgrade over Sonnet 5, runs more than 30% faster, and costs up to 30% less for most work.
It’s a clear upgrade over Sonnet 5, runs more than 30% faster, and costs up to 30% less for most work.
6:36 PM UTC · Sep 28, 2026 · 422K Views
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