Claude Opus 5.5 launches with promised running costs 40% below Opus 5

Anthropic announced Claude Opus 5.5's availability on September 22, 2026. It says the first model in its Claude 5.5 family performs at Claude Fable 5.1's level for most tasks and costs 40% less to run than Opus 5.

Every reports that game interfaces, 3D, animations and prototypes delivered its best one-shot results during a week of testing. The publisher recommends defining what “done” means and asking for the main deliverable first. In one 10-minute scheduling task, it says, the model built a data generator and handouts, then ran out of time before making the schedule.