AI model launches · Anthropic
Claude Opus 5.5 launch
Anthropic introduces Claude Opus 5.5, the first model in its Claude 5.5 family, pitched as Fable 5.1-level quality at 40% less than Opus 5.
Claude @claudeai · 22 Sept 2026From the post
Introducing Claude Opus 5.5, the first model in our new Claude 5.5 family. It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.
Claude @claudeai on X · 22 Sept 2026