Like before, Fable 5.2 will be available on all platforms today, including Amazon Web Services, Google Cloud, and Microsoft Azure, while direct access to Mythos remains limited to organizations in Anthropic's Cyber and Life Sciences verification programs. Also like before, Fabe and Mythos share the same underlying model, but Fable ships with stricter cybersecurity and biology safeguards.
It's maybe a bit of a surprise that Anthropic didn't designate these models as "5.5," given that its Claude Opus, Sonnet, and Haiku models are now at that version number. The company stresses that it continues to recommend that users go with Opus 5.5 for most coding and knowledge tasks, while Fable 5.2 is meant to help users "tackle the most daunting technical challenges."
And while both models show improvements in coding, reasoning, and vision, according to Anthropic, one feature the company is stressing here is speed. Fable 5.2 and Mythos 5.2, the company says, generate output up to 30 percent faster than Fable 5.1 and Mythos 5.1, respectively.
