# Claude Sonnet 4.5: AI model fact sheet

- **Provider:** anthropic
- **Released:** 2025-09-29
- **Context window:** 200,000 tokens
- **API pricing:** $3.00 / 1M input, $15.00 / 1M output
- **OpenRouter ID:** anthropic/claude-4.5-sonnet
- **Capabilities:** conversation, reasoning, code-generation, analysis, agentic-tool-use

Claude Sonnet 4.5 is Anthropic's most advanced Sonnet model to date, optimized for real-world agents and coding workflows. Stronger agentic capabilities, speculative parallel execution, efficient memory and tool orchestration.

## Benchmarks

| Benchmark | Score |
| --- | --- |
| SWE-bench Verified | 77.2% |

Source: real side-by-side outputs, pricing and specs at https://rival.tips/models/claude-4.5-sonnet