Anthropic Claude: Claude Sonnet 4.6 API
Claude Sonnet 4.6 is the mid-tier workhorse of Anthropic's 4.6 generation, bringing a 1M-token context window and 128K single-response output to the Sonnet price point. It uses the same adaptive thinking architecture as Opus 4.6, deciding reasoning depth on its own based on task complexity. It improves clearly over Sonnet 4.5 on coding, agentic workflows and long-document work while keeping the speed and cost profile the Sonnet line is known for.
- Context window: 1,000,000 tokens
- Max output: 128,000 tokens
- Input: text, image, file
- Output: text
- Reasoning: Supported
- Tool calling: Supported
- File input: Supported
- Released: 2026-02-17
- Knowledge cutoff: 2025-08-31
Frequently Asked Questions
What is the context window of Claude Sonnet 4.6?
Claude Sonnet 4.6 supports a context window of up to 1,000,000 tokens.
Does Claude Sonnet 4.6 support function calling?
Yes. Claude Sonnet 4.6 supports tool / function calling.
Does Claude Sonnet 4.6 support reasoning?
Yes. Claude Sonnet 4.6 is a reasoning-capable model.
What is the knowledge cutoff of Claude Sonnet 4.6?
The knowledge cutoff of Claude Sonnet 4.6 is 2025-08-31.