Anthropic Launches Claude Opus 5.5, First Model in New 5.5 Family

Anthropic launched Claude Opus 5.5, the first model in its new 5.5 family, saying it performs at roughly the level of Claude Fable 5.1 on most tasks while costing 40% less to run than Opus 5 and generating output more than 30% faster.
The company said Opus 5.5 brings major gains in agentic coding, computer use, and knowledge work. Pricing is set at $20 per million output tokens, with cache reads at $0.20 per million, 60% cheaper than Opus 5.
On benchmarks, Anthropic reported Opus 5.5 scored 66.4% on Terminal-Bench 4.0 versus 52.3% for Opus 5, 57.8% on CursorBench 4.0 versus 46.6%, 1846 on GDPval-AA versus 1708, and 81.8% on OSWorld 2.0 versus 74.0%. In one test, the model reportedly audited and fixed a 200K-line codebase in under three hours, compared with more than 20 hours for Opus 5.
Anthropic also said Opus 5.5 scored best among its recent models on its behavioral alignment audit and attempted to cross containment boundaries about 85% less often than Opus 5 or Mythos 5.1. The model is available now across Claude, AWS, Google Cloud, and Microsoft Azure, with Claude Sonnet 5.5 and Haiku 5.5 expected in the coming weeks.