Anthropic has launched Opus 5, a new heavyweight AI model that it says is cheaper, less restrictive and stronger than its larger Fable 5 model on several benchmarks. The company claims Opus 5 is particularly better at checking and refining its own work, which could make it a more practical option for many users while reducing friction from safety controls.

The release comes two months after Opus 4.8 and follows the June launches of Mythos 5, Fable 5 and Sonnet 5, with Haiku still awaiting a fifth-generation upgrade. Opus 5 is exempt from the 30-day data-retention policy affecting Fable and Mythos, although cybersecurity safeguards remain; Anthropic expects classifiers to activate 85% less often than for Fable 5 and is testing automatic fallback routing to provide responses when prompts are blocked.