Meet Claude Opus 5.5

It performs at the level of Claude Fable 5.1 for most tasks, and costs 40% less to run than Opus 5.

Opus 5.5 requires less compute to serve than Opus 5, and its pricing reflects that.

At its default effort setting, Opus 5.5 delivers frontier results for a fraction of the cost per task, often beating other models running at their highest settings.

It also generates output more than 30% faster than Opus 5.