Anthropic launches Claude Opus 5.5, cutting inference costs 40% versus Opus 5

Anthropic released Claude Opus 5.5, the first entry in its 5.5 model family, matching the performance of Claude Fable 5.1 on most tasks while running 40% cheaper than its predecessor, Opus 5. The model underwent external evaluation by groups including Frontier Design and METR, and scored higher than any prior Anthropic model on the company's internal automated behavioral audit for alignment and safety.