Claude Fable 5 has arrived, promising a major leap in AI performance. Here’s what makes it powerful, how it compares, and why it matters.
AIニュース

Meet Claude Fable 5, Anthropic’s New Mythos-Class Model

On June 9, 2026, Anthropic released Claude Fable 5, the first model in a brand new top tier the company calls the Mythos class. This is not another point upgrade in the Opus line. Anthropic describes Fable 5 as a model that sits above Opus in raw capability. It is state of the art on nearly every benchmark it was tested on, and it is the most powerful model the company has ever made available to the general public. It launched alongside a sibling model, Claude Mythos 5. That model is the same underlying system with the safety guardrails lifted, available only to a small set of vetted users. Fable […]