Anthropic releases Claude Opus 5.5 with performance matching Fable 5.1 at 60% lower cost

Anthropic has launched Claude Opus 5.5, the first model in its 5.5 series. The company stated that the new model matches the performance of its flagship Claude Fable 5.1 while reducing operating costs by 20% compared to Opus 5 and 60% compared to Fable 5.1. Pricing is set at $4 per million tokens for input and $20 for output, with cache read prices at $0.2 per million. In benchmarks, Opus 5.5 outperformed Fable 5.1 and GPT-6 Astra in Terminal-Bench 4, FrontierCode, and GDPval-AA v2.1, though it trails GPT-6 Astra in AutomationBench and Terminal-Bench-Science 0.1. This release follows CEO Dario Amodei's call for slower AI development and maintains the same cybersecurity and biosafety protocols as Fable 5.1.