Opus 5 vs. Fable 5: What does half the price buy?

A comparison of Anthropic’s Claude Opus 5 and Claude Fable 5 found Opus 5 to be cheaper and sometimes faster.

But Fable 5 performed better on bug-hunt tasks and explanation-heavy reasoning, showing stronger overall reasoning in tests.

Anthropic also said Opus 5 is not more capable overall, despite marketing that frames it as near-frontier performance at a lower price.

The result highlights the tradeoff buyers face between cost, reliability, and model capability when choosing an AI model.