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.
| Creator | Anthropic |
| Release Date | May, 2025 |
| License | Proprietary |
| Context Window | 1,000,000 |
| Image Input Support | Yes |
| Open Source (Weights) | No |
| Input Cost | $15/M tokens |
| Output Cost | $75/M tokens |
