# Claude Sonnet 5.5: AI model fact sheet

- **Provider:** anthropic
- **Released:** 2026-09-28
- **Context window:** 1,000,000 tokens
- **API pricing:** $2.00 / 1M input, $10.00 / 1M output
- **OpenRouter ID:** anthropic/claude-sonnet-5.5
- **Capabilities:** conversation, reasoning, code-generation, analysis, agentic-tool-use, tool-use

Anthropic's direct upgrade to Sonnet 5 for everyday coding and knowledge work. Anthropic says it writes output more than 30% faster than Sonnet 5 and finishes tasks with fewer tokens and tool calls, at the same price and a 1M-token context, with text, image and file input.

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/claude-sonnet-5.5