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Anthropic: Claude Sonnet 4

anthropic/claude-sonnet-4

Created May 22, 20251,000,000 context
Starting at $3/M input tokensStarting at $15/M output tokens

Claude Sonnet 4 significantly enhances the capabilities of its predecessor, Sonnet 3.7, excelling in both coding and reasoning tasks with improved precision and controllability. Achieving state-of-the-art performance on SWE-bench (72.7%), Sonnet 4 balances capability and computational efficiency, making it suitable for a broad range of applications from routine coding tasks to complex software development projects. Key enhancements include improved autonomous codebase navigation, reduced error rates in agent-driven workflows, and increased reliability in following intricate instructions. Sonnet 4 is optimized for practical everyday use, providing advanced reasoning capabilities while maintaining efficiency and responsiveness in diverse internal and external scenarios.

Read more at the blog post here

Providers for Claude Sonnet 4

OpenRouter routes requests to the best providers that are able to handle your prompt size and parameters, with fallbacks to maximize uptime.

Performance for Claude Sonnet 4

Compare different providers across OpenRouter

Apps using Claude Sonnet 4

Top public apps this month

Recent activity on Claude Sonnet 4

Total usage per day on OpenRouter

Prompt
2.09B
Completion
122M
Reasoning
3.36M

Prompt tokens measure input size. Reasoning tokens show internal thinking before a response. Completion tokens reflect total output length.

Uptime stats for Claude Sonnet 4

Uptime stats for Claude Sonnet 4 across all providers

Sample code and API for Claude Sonnet 4

OpenRouter normalizes requests and responses across providers for you.

OpenRouter provides an OpenAI-compatible completion API to 400+ models & providers that you can call directly, or using the OpenAI SDK. Additionally, some third-party SDKs are available.

In the examples below, the OpenRouter-specific headers are optional. Setting them allows your app to appear on the OpenRouter leaderboards.

Using third-party SDKs

For information about using third-party SDKs and frameworks with OpenRouter, please see our frameworks documentation.

See the Request docs for all possible fields, and Parameters for explanations of specific sampling parameters.