Anthropic launches Claude Fable 5.1 and says it’s up to 45 percent cheaper for agentic work
AITopTools Editorial TeamSeptember 1, 2026
What changed
Anthropic has launched its Fable 5.1 and Mythos 5.1 AI models. The company says Fable 5.1 performs better than Fable 5 and costs about 25 percent less in typical use, or up to 45 percent less for complex tasks carried out in multiple steps.
What this means for you
The lower prices could make Anthropic’s models more practical for businesses and developers building systems that handle multi-step work. Anthropic also says the update responds to customer concerns about data retention and overly restrictive safety limits, though the supplied information does not detail those changes.