Anthropic releases Opus 5.5 with lower prices and Fable-level performance

Anthropic unveiled Opus 5.5 on Tuesday, announcing that it outperforms the Fable model in coding and knowledge work benchmarks. The release also boasts lower prices, with output tokens charged at $20 per million tokens, a $5 drop from the previous model's $25 rate. Opus 5.5 is quicker to run, reflecting reduced compute requirements, and communicates in a less jargon-filled, more direct manner.

Just two months after Opus 5's release on July 24th, Anthropic plans to roll out Sonnet 5.5 and Haiku 5.5 with similar enhancements. The new model's biological and cybersecurity capabilities are on par with Mythos, prompting similar safety measures as Fable. Launched as CEO Dario Amodei advocates for responsible AI development, Opus 5.5 undergoes rigorous alignment testing and pre-release evaluation by independent groups like METR and Frontier Design.

However, Anthropic hints at more advanced training and monitoring systems for forthcoming models, emphasizing the need for robust public policy to ensure AI safety as capabilities advance.