Claude Opus 5.5

Anthropic's current Opus model for long-running knowledge work and complex tasks.

Last checked 24 September 2026 · where this came from

Where it sits

No editor has recorded what came before or after this model. That is not the same as it standing alone — it means we have not established the link from a maker’s announcement yet.

Others in the Claude family

Claude Sonnet 5Anthropic's current Sonnet model for general work with a balance of speed and capability.

What changed, and when

One record, written when we started tracking this model. Nothing has changed since, though we have only been watching it since 26 September 2026.

26 September 2026Current record
Claude Opus 5.5 — available
The first record we wrote for this model.
Typed in by a person from the maker's pages when the registry was started.
The source we readread 24 September 2026