Anthropic has launched Claude Opus 5.5, its latest artificial intelligence model, as competition intensifies among AI companies to deliver more capable systems for software development and other complex tasks.
The model, released on September 22, is the latest addition to Anthropic’s Claude lineup and comes amid growing debate over the pace at which increasingly capable AI systems are being developed and deployed.
Anthropic said Opus 5.5 costs about 40% less to run than its predecessor on typical workloads. The model is priced at $4 per million input tokens and $20 per million output tokens, representing a 20% reduction from Opus 5.
The company said the model is designed for complex software development and long-running tasks. Anthropic reported that Opus 5.5 can handle large codebase migrations, identify software inefficiencies and perform extended agentic coding tasks.
In one example cited by the company, an early tester used Opus 5.5 on a 680,000-line code migration in less than a day, which Anthropic said would previously have taken an engineering team weeks.
Anthropic said Opus 5.5 also underwent external testing by AI safety research groups Frontier Design and METR before its release.
The company said the model performed better than earlier systems in its internal safety tests and was less likely to attempt to bypass containment boundaries during a dedicated evaluation.
The release comes shortly after Anthropic CEO Dario Amodei called for the AI industry to slow the development of new capabilities to allow safety measures to keep pace with advances in the technology.
Opus 5.5 also includes safeguards designed for high-risk applications, including cybersecurity and biological research, according to Anthropic.
The company is expanding access to the model for vetted cybersecurity and life-sciences researchers through dedicated programmes.
Opus 5.5 is available through Anthropic’s platform as well as Amazon Web Services, Google Cloud and Microsoft Azure. Anthropic said Claude Sonnet 5.5 and Claude Haiku 5.5 will be released in the coming weeks.
