Today Anthropic released its new Opus 5 model, which the company claims delivers performance comparable to its more advanced Fable 5 model at half the price.
Opus 5 is designed for both complex coding and general office work. Anthropic says the model can make its way through the steps of a complicated problem without much back-and-forth with the user. Plus, it can check its own work and recover from errors rather than getting stuck. It also shows improvements over its predecessor, Opus 4.8, in complex coding tasks. The company calls it its strongest model yet for general knowledge work.
A broader range of professional tasks
The release is part of Anthropic’s effort to expand Claude beyond chat and code generation, and into a broader range of professional tasks, including design, marketing, accounting, and the analysis of large document sets.
What makes Opus 5 notable, however, is its proximity to Fable 5, the most advanced model Anthropic has made broadly available. Fable is significantly better than previous releases at writing software, working through long projects with limited supervision, and handling especially difficult assignments. The U.S. government even became alarmed at the model’s capacity to discover and exploit software vulnerabilities in cyberattacks. (Fable 5 is the public version of another Anthropic model, Mythos 5, which is even better at cyber defense—and offense—and available only to the government and select organizations working on cybersecurity and critical infrastructure.)
Scientific research
Opus 5 costs $5 per million input tokens and $25 per million output tokens. An API customer might use it for routine coding or general office tasks, then switch to the more powerful and more expensive Fable 5 model for the hardest work.
Anthropic also says Opus 5 is its most capable generally available model for scientific research, citing performance gains on biology tasks compared with Opus 4.8. The company said this could benefit researchers integrating the model into engineering and analysis work.
The model includes adjustable effort levels—low, medium, and high—so that users can make their own trade-offs between cost and capability. Anthropic says Opus 5 is its most cost-efficient model on the DeepSearchQA and Humanity’s Last Exam benchmarks for models that use tools.
Anthropic is offering Opus 5 “fast mode” (available in the Claude chatbot and Claude Code), which offers 2.5 times faster output token generation at about twice the standard price of the model. The company is releasing the feature as a “research preview” to all API users, with the aim of collecting data on how and when people use it.
Opus 5 will be the default model for users with Claude Max subscriptions, Anthropic says, with standard token limits on all paid plans.