Anthropic Launches Claude Opus 5.5 With Fable-Level Performance at a Lower Price

Anthropic today launched Claude Opus 5.5, which it says is the first model in a new 5.5 model family. Opus 5.5 performs at the level of Claude Fable 5.1 on most work, but costs 40 percent less to run than Opus 5. According to Anthropic, Opus 5.5 is a "major step up" from Opus 5 with improvements in performance and safety. Opus 5.5 is comparable to Mythos 5.1 in biology and cybersecurity, so Anthropic is launching it with safeguards similar to those on Fable 5.1. Opus 5.5 also generates output over 30 percent faster than Opus 5. On benchmarks shared by Anthropic, Opus 5.5 surpassed Fable 5.1 on agentic coding, knowledge work, computer use, visual chart recognition, and multidisciplinary reasoning. Anthropic says the model communicates more naturally than prior models, putting important information at the front of a response so it's easier to understand at a glance. It is less likely to use jargon or idiosyncratic phrases, and it follows the writing rules it's given. Claude Op