Claude Sonnet 4

Anthropic · Released May 2025 · Knowledge cutoff January 2025

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%),...

It belongs to Anthropic's Claude family: Opus is the deep-capability tier, Sonnet balances quality and speed, Haiku is the light tier, and Fast servings trade some depth for latency.

Facts and pricing

Provider

Anthropic

Context window

1M tokens

Input price

33.0 credits / 1M tokens ($3.00 raw)

Output price

165 credits / 1M tokens ($15.00 raw)

Vision (image input)

Yes

Tool calling

Yes

Extended reasoning

No

Credits are what Zeplik bills: 1 credit = $0.10, computed from the raw provider rate with a 1.10x margin. Raw prices shown per 1M tokens.

Try Claude Sonnet 4 now

What Claude Sonnet 4 is best for

• Hard problems where answer quality matters more than cost: strategy, analysis, difficult writing
• Very long documents and codebases: a 1M-token window fits entire books or repositories in one conversation
• Working with images: screenshots, charts, photos and scanned documents alongside text
• Tool use and agents: reliably calls functions, so it can search, run skills and drive workflows

Example prompts

Prompts that suit a frontier model like Claude Sonnet 4:

• Review this business plan and give me the three hardest questions an investor would ask
• Rewrite this announcement so it lands with both engineers and executives
• I am choosing between two job offers, help me think through the tradeoffs
• Draft a technical design doc for a rate limiter, including failure modes

Anthropic family

All 15 Anthropic models

Frequently asked questions

What is Claude Sonnet 4?

Claude Sonnet 4 is an AI model by Anthropic. 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%),...

How much does Claude Sonnet 4 cost on Zeplik?

Input tokens cost 33.0 credits per million and output tokens 165 credits per million (1 credit = $0.10; the raw provider rates are $3.00 and $15.00 per million). New accounts start with free credits.

How long can a conversation with Claude Sonnet 4 be?

Claude Sonnet 4 has a 1M-token context window (1,000,000 tokens), which covers the conversation plus any documents you attach.

Does Claude Sonnet 4 support images and tools?

Claude Sonnet 4 accepts image input and supports tool calling.

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