Anthropic has launched Claude Opus 5.5, the first model in its new Claude 5.5 family, with the company targeting major improvements in coding, AI agents and professional knowledge work.
Released on September 22, Claude Opus 5.5 is designed for long-running, complex tasks and is positioned by Anthropic as a significant upgrade over its previous Opus 5 model. The company says the new model performs at the level of Claude Fable 5.1 on most work while costing about 40% less to run than Opus 5.
One of the biggest changes is its focus on software development and autonomous AI agents. Anthropic says early testing showed Opus 5.5 handling demanding engineering tasks, including a 680,000-line code migration that one tester completed in less than a day. The model also features a 1-million-token context window and can generate up to 128,000 tokens in a single response.
The model is also cheaper and faster to operate. Anthropic lists pricing at $4 per million input tokens and $20 per million output tokens, while cache reads cost $0.20 per million tokens. The company says Opus 5.5 generates output more than 30% faster than Opus 5 and uses less computing power on typical workloads.
Safety is another major focus of the release. Anthropic says Opus 5.5 underwent external testing by organizations including Frontier Design and METR before launch and includes safeguards developed for its most capable models. The company is also expanding controlled access for vetted cybersecurity and life-sciences researchers.
Claude Opus 5.5 is now available through Anthropic’s Claude platform, as well as Amazon Web Services, Google Cloud and Microsoft Foundry. Anthropic says Claude Sonnet 5.5 and Claude Haiku 5.5 are expected to follow in the coming weeks.
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