Claude Sonnet 4

Abstract

Claude Sonnet 4 can understand nuanced instructions and context, recognize and correct its own mistakes, and create sophisticated analysis and insights from complex data. Combined with superior coding, vision, and writing skills, you can use Claude Sonnet 4 for a variety of use cases. Claude Sonnet 4 can produce near-instant responses or extended, step-by-step thinking that is made visible to the user. API users also have fine-grained control over how long the model thinks for.