Claude Sonnet 4 API is Anthropic’s entry-level Claude 4 model endpointthat offers hybrid “instant response” and extended “summarized thinking” modes for advanced coding, reasoning, and agentic workflows at competitive token-based pricing.
Overview
Claude Sonnet 4 is the latest addition to Anthropic’s Claude family of large language models (LLMs), unveiled on May 22, 2025. Positioned as a cost-effective and efficient model, Claude Sonnet 4 serves as a successor to Claude 3.7 Sonnet, offering enhanced capabilities in coding, reasoning, and precision.
Key Features of Claude Sonnet 4
- Hybrid Reasoning Architecture: Claude Sonnet 4 employs a hybrid reasoning approach, combining rapid response generation with extended, step-by-step thinking. This dual-mode processing allows the model to adapt its reasoning depth based on task complexity.
- : The model demonstrates significant improvements in coding tasks, complex problem-solving, and precise instruction following compared to its predecessors.
