Introducing Claude Sonnet 5

Claude Sonnet 5 is a new AI model designed for agentic tasks, such as planning, using software tools, and executing complex workflows autonomously. It offers a significant performance boost over its predecessor, Sonnet 4.6, narrowing the capability gap between the Sonnet and Opus model classes. In many evaluations, Sonnet 5 matches the performance of the more expensive Opus 4.8 while providing better cost efficiency.

The model is built to handle multi-step technical tasks, including coding, debugging, and data analysis, with improved reliability and follow-through. Safety assessments indicate that Sonnet 5 exhibits fewer undesirable behaviors than previous versions and is better at resisting prompt injection and malicious requests. While it possesses some routine technical skills, it is not designed for advanced cybersecurity tasks and includes default safeguards to block potentially dangerous usage.

Claude Sonnet 5 is available immediately across all user plans and through the Claude API. It features introductory pricing of $2 per million input tokens and $10 per million output tokens through August 31, 2026, after which standard pricing of $3 and $15 per million tokens will apply. The model is intended to provide enterprise users and developers with a scalable, high-performance option for automating complex, real-world operations.