Introducing Claude Sonnet 5

Claude Sonnet 5 is an agentic AI model designed to perform complex tasks like planning, coding, and using digital tools such as browsers and terminals. It offers a significant performance boost over its predecessor, Sonnet 4.6, and provides capabilities that approach the level of the more powerful Opus 4.8 model while maintaining a lower cost.

The model is built to handle multi-step workflows, such as software engineering and data analysis, with improved reasoning and tool-use accuracy. It is capable of working autonomously on tasks that previously required larger, more expensive models. Safety evaluations indicate that Sonnet 5 exhibits fewer undesirable behaviors than Sonnet 4.6, and it includes built-in safeguards to prevent misuse in cybersecurity contexts.

Claude Sonnet 5 is available immediately across all Claude plans and through the Claude API. It features introductory pricing of $2 per million input tokens and $10 per million output tokens until August 31, 2026, after which prices will increase to $3 and $15 per million tokens, respectively. This release aims to provide developers and enterprise users with a more efficient, cost-effective option for scaling complex, agentic AI operations.