Is Claude Sonnet 4 available on FastMetal?

Not at the moment. Claude Sonnet 5, from the same lab, is available on the FastMetal API today.

What is the context window of Claude Sonnet 4?

1,000,000 tokens, shared between the prompt and the response.

How does Claude Sonnet 4 rank?

#122 on the public arena's Japanese board (ELO 1,343). Ranks move as the leaderboard is updated.

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anthropic/claude-sonnet-4

Not Available

Claude Sonnet 4

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](https://www.anthropic.com/news/claude-4)

5/22/2025

1,000,000 tokens

#81 Vision (Overall)

Specifications

Modalities

Input

image

text

file

Output

text

Supported Parameters

include_reasoning

max_tokens

reasoning

stop

temperature

tool_choice

tools

top_k

top_p

Max Output Tokens

64,000

Frequently asked questions

Is Claude Sonnet 4 available on FastMetal?: Not at the moment. Claude Sonnet 5, from the same lab, is available on the FastMetal API today.
What is the context window of Claude Sonnet 4?: 1,000,000 tokens, shared between the prompt and the response.
How does Claude Sonnet 4 rank?: #122 on the public arena's Japanese board (ELO 1,343). Ranks move as the leaderboard is updated.