# ClaudeDevs Announces Release of Claude Sonnet 5.5

Anthropic published a developer guide covering migration from Sonnet 5, tuning effort, and usage in Claude Code.

- Includes guidance on choosing between Sonnet 5.5 and Opus 5.5
- Details migration steps from Sonnet 5 and how to tune effort
- Explains how to use the new model in Claude Code

## Why it matters

Developers building on Claude can now migrate existing Sonnet 5 workloads to Sonnet 5.5 and deploy it in Claude Code.

## Sources

- [Anthropic: ClaudeDevs Announces Release of Claude Sonnet 5.5](https://x.com/ClaudeDevs/status/2104687805876367793)

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Summarized by dstilled on 2026-09-28. https://dstilled.ai/story/6b0d0a58-bf73-4871-ab03-0ebfd17c11ba