# claude-sonnet-5-5

Anthropic



Second Claude 5.5 family model \(2026-09-28\); ~30%+ faster output vs Sonnet 5 and up to ~30% lower cost per typical task; same list price as Sonnet 5: $2/$10 /MTok \(cache read $0.20, write $2.50\); Adaptive thinking \(default effort High on API / Medium in apps\); large coding & knowledge-work gains vs Sonnet 5; ships with Opus-class cyber safeguards + preserved thinking; Haiku 5.5 coming weeks


## Availability

Claude API/Platform claude-sonnet-5-5; Amazon Bedrock / Google Cloud / Microsoft Azure; Claude.ai / Claude Code apps; Cursor
- Model released: Sep 28, 2026 · Date only
- Review updated: Sep 29, 2026 07:45 Tue · Beijing Time (UTC+8)

## Sources

- Introducing Claude Sonnet 5.5: https://www.anthropic.com/claude-sonnet-5-5
- Models overview — Claude Sonnet 5.5 specs: https://docs.anthropic.com/en/docs/about-claude/models/overview

Canonical entry: https://www.ailyre.com/source/?id=anthropic-claude-sonnet-5-5&lang=en