Claude Fable 5.1 Launches With Lower Prices, Better Safeguards

Anthropic has introduced Claude Fable 5.1 and Claude Mythos 5.1, described as the world's most advanced models for coding and knowledge work. The two are the same underlying model with different safeguard levels: Fable 5.1 is publicly available, while Mythos 5.1 is restricted to trusted programs focused on cybersecurity and life sciences. Fable 5.1 costs roughly 25% less than its predecessor for typical workloads, with savings up to 45% for agentic tasks. New Enterprise Frontier Safeguards offer complete customer data privacy, and improved filters cut cybersecurity false positives by 60%. The model also sets new performance benchmarks across coding, scientific research, and business automation.