Claude Sonnet 4 is a next-generation model from Anthropic, significantly enhancing coding and reasoning capabilities over its predecessor. It achieves state-of-the-art performance on SWE-bench, balances capability and computational efficiency, and is optimized for both routine and complex software development projects. Key features include improved codebase navigation, reduced error rates, and increased reliability in following intricate instructions.
Retired on Oct 22, 2026: requests to this model ID now return an error. These models are live and work with the same API key.
Claude Sonnet 4 is a next-generation model from Anthropic, significantly enhancing coding and reasoning capabilities over its predecessor. It achieves state-of-the-art performance on SWE-bench, balances capability and computational efficiency, and is optimized for both routine and complex software development projects.
No. Claude Sonnet 4 was retired on NagaAI on Oct 22, 2026, and requests to it now return an error. Live models you can use instead with the same API key: Claude Haiku 5.5, Claude Sonnet 5.5 and Claude Opus 5.5.
It takes text, images and files as input and returns text.
