Claude Opus 5 is Anthropic's July 2026 Opus flagship—near–Fable 5 intelligence at half the price, and the new default on Claude Max. Our assistant tests treat it like a distilled Fable that actually finishes work: outstanding helpfulness, instruction following, and comprehension for everyday tasks and long agent runs, with Fable-adjacent warmth. Creative writing is the clear miss—prose comes out flatter and less literary than Fable 5 or recent Opus releases, so we score it poorly there on purpose. Reach for Opus 5 when you want frontier judgment without Mythos pricing; pick Fable when voice and fiction matter.