Anthropic releases Opus 5.5 at $20, beating Fable

Anthropic's Opus line sits at the top of its three-tier lineup, with Sonnet in the middle and Haiku as the fastest and cheapest option. The company says Opus 5.5 outpaces the larger Fable model in many benchmarks and completed several informal tasks that Fable failed. The previous Opus 5 launched on July 24, making this a two-month cadence between top-tier releases.

The price cut to $20 per million output tokens, down from $25, and the faster run time reflect an overall drop in the compute required to serve the model. Anthropic also changed how Opus communicates, making it less likely to use jargon and more likely to lead with important information. Opus 5.5 is comparable to Mythos in biology and cybersecurity capabilities, so it carries the same safeguards as Fable, limiting use for discovering exploits in compiled programs or developing recognizable biological weapons.

The launch is Anthropic's first since CEO Dario Amodei embraced calls to pace the frontier, deliberately slowing capability progress to let alignment and risk prevention keep up. Whether that stance shapes future releases may hinge on whether the promised Sonnet 5.5 and Haiku 5.5 arrive with similar performance gains in the coming weeks.