Claude Sonnet 5.5 · model releaseClaude Sonnet 5.5

Valid from

2026-09-28

Valid until

still holds

Published

no source on record carries a date

Recorded by AsOf

2026-11-04

Checked

2026-11-04 · its source page states the value and the date

Confidence

0.95

Sources

“September 28, 2026 We’ve launched Claude Sonnet 5.5 ( claude-sonnet-5-5 ).”— what the page says, read 2026-11-04

• https://platform.claude.com/docs/en/release-notes/overviewprimary · platform.claude.com

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