Claude Sonnet 4
Summary
Claude Sonnet 4 is a proprietary language model from Anthropic, released on 22 May 2025. It accepts images, text and PDFs and generates text, with a 200K-token context window and up to 64K output tokens per response. As of 4 Oct 2026, the lowest listed API price is $3 per million input tokens and $15 per million output tokens (OpenRouter), across 2 providers we track.
Balanced Claude model for coding, analysis, agent workflows, and cost control
Last verified 4 Oct 2026. Every figure on this page links to its source.
Specifications
| Developer | Anthropic |
|---|---|
| Release date | 22 May 2025 [models.dev] |
| Status | Generally available [models.dev] |
| Weights | Proprietary (API only) [models.dev] |
| Context window | 200K (200,000 tokens) [models.dev] |
| Max output | 64K tokens [models.dev] |
| Knowledge cutoff | 31 Jan 2025 [models.dev] |
| Input | Images, text and PDFs [models.dev] |
| Output | Text [models.dev] |
| Reasoning mode | Yes [models.dev] |
| Tool calling | Yes [models.dev] |
| Structured output | No [models.dev] |
Claude Sonnet 4 API pricing by provider
USD per million tokens. Sorted by input price.
| Provider | Input | Output | Cached input | Context | Source |
|---|---|---|---|---|---|
| OpenRouter anthropic/claude-sonnet-4 | $3 | $15 | $0.30 | 200K | OpenRouter, 4 Oct 2026 |
| Vercel AI Gateway anthropic/claude-sonnet-4 | $3 | $15 | $0.30 | 1M | models.dev, 4 Oct 2026 |
Frequently asked questions
What is the context window of Claude Sonnet 4?
Claude Sonnet 4 has a context window of 200,000 tokens (200K) and can generate up to 64,000 tokens in a single response, according to models.dev.
How much does the Claude Sonnet 4 API cost?
Claude Sonnet 4 is listed from $3 per million input tokens and $15 per million output tokens (OpenRouter). Prices last verified 4 Oct 2026.
Is Claude Sonnet 4 open source?
No. Claude Sonnet 4 is a proprietary model; Anthropic has not released its weights. It is available through APIs including OpenRouter, Vercel AI Gateway.
When was Claude Sonnet 4 released?
Anthropic released Claude Sonnet 4 on 22 May 2025, according to models.dev.
Which providers offer Claude Sonnet 4?
We track Claude Sonnet 4 on 2 providers: OpenRouter, Vercel AI Gateway.
Change history
No changes detected since we started tracking this model. We re-check every source daily.