Anthropic launches Claude Opus 5.5: Fable 5.1-level performance at 40% lower cost than Opus 5

bcherny · x · 2026-09-23

Anthropic announced Claude Opus 5.5, the first model in its new Claude 5.5 family. It reportedly performs at the level of Claude Fable 5.1 on most tasks while costing 40% less to run than Opus 5. Reposting, dsp said he rarely comments on model launches but found 5.5 clearer, more concise, highly capable and much cheaper, and has been using it heavily.

Related event: Anthropic Launches Claude Opus 5.5: Cheaper, Faster, and Fable 5.1-Level(75 posts)→

Original post →

More from Models

Models channel →