Anthropic: Claude Sonnet 4

Claude Sonnet 4 builds on the strengths of Sonnet 3.7, delivering major improvements in coding and reasoning with greater precision and controllability. It achieves state-of-the-art results on SWE-bench (72.7%), striking an effective balance between advanced capability and computational efficiency.

Key upgrades include better autonomous codebase navigation, lower error rates in agent-driven workflows, and stronger reliability in handling complex instructions. Optimized for real-world use, Sonnet 4 offers advanced reasoning power while remaining efficient and responsive across a wide range of coding, software development, and general-purpose tasks.