Claude Opus 5.5 · context window1M tokens

Valid from

2026-09-22

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 22, 2026 We’ve launched Claude Opus 5.5 ( claude-opus-5-5 ), a model for long-running agentic coding and knowledge work. It has a 1M token context window by default”— what the page says, read 2026-11-04

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

/claim/clm_C8F8497EE25C.md/v1/claims/clm_C8F8497EE25Ctimelinesubmit a correction