ForecastAnthropiclanguage model

Claude Opus 5.1 has not been announced. Based on how often Anthropic ships new versions, our forecast is that it arrives around November 14, 2026, probably between October 30, 2026 and December 19, 2026.

The forecast

Most likely	November 14, 2026
Window	October 30, 2026 to December 19, 2026
Chance it arrives in that window	About 54%
Follows	Claude Opus 5 (out July 24, 2026)
Based on	3 earlier gaps between versions

How we got this

Anthropic is the maker of Claude Opus 5. We look at the gaps between its earlier versions (Claude Opus 4.6, 2026-02-04; Claude Opus 4.7, 2026-04-16; Claude Opus 4.8, 2026-05-27; Claude Opus 5, 2026-07-24) and project the next one. It is a guess from a pattern, not news: the maker has not said Claude Opus 5.1 exists. This page turns into the launch page, with price and facts, as soon as the model shows up on OpenRouter, Hugging Face or GitHub.

Available now from Anthropic

Predicted automatically by Modelcast. Not affiliated with Anthropic.