# Claude Sonnet 4.5

> Claude Sonnet 4.5 is a proprietary language model from Anthropic, released on 29 Sept 2025. It accepts text, images and PDFs and generates text, with a 1M-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 (Claude API), across 9 providers we track.

Source page: https://www.aimodel.directory/models/claude-sonnet-4-5
Last verified: 4 Oct 2026

## Specifications

- **Developer:** Anthropic
- **Release date:** 29 Sept 2025 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Status:** Generally available (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Weights:** Proprietary (API only) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Context window:** 1M (1,000,000 tokens) (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Max output:** 64K tokens (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Knowledge cutoff:** 31 Jul 2025 (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Input:** Text, images and PDFs (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Output:** Text (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Reasoning mode:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Tool calling:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)
- **Structured output:** Yes (source: models.dev, https://github.com/sst/models.dev/blob/dev/providers/anthropic/models/claude-sonnet-4-5.toml)

## API pricing (USD per 1M tokens)

| Provider | Input | Output | Cached input | Context |
|---|---|---|---|---|
| Claude API | $3 | $15 | $0.30 | 1M |
| Claude API | $3 | $15 | $0.30 | 1M |
| Databricks | $3 | $15 | $0.30 | 200K |
| Databricks | $3 | $15 | $0.30 | 200K |
| Azure AI Foundry | $3 | $15 | $0.30 | 200K |
| Vertex AI (Claude) | $3 | $15 | $0.30 | 200K |
| Amazon Bedrock | $3 | $15 | $0.30 | 200K |
| Google Vertex AI | $3 | $15 | $0.30 | 200K |
| Amazon Bedrock | $3 | $15 | $0.30 | 200K |
| OpenRouter | $3 | $15 | $0.30 | 1M |
| Vercel AI Gateway | $3 | $15 | $0.30 | 1M |
| Amazon Bedrock | $3.30 | $16.50 | $0.33 | 200K |
| Amazon Bedrock | $3.30 | $16.50 | $0.33 | 200K |
| Amazon Bedrock | $3.30 | $16.50 | $0.33 | 200K |
| Amazon Bedrock | $3.30 | $16.50 | $0.33 | 200K |
| Snowflake Cortex | – | – | – | 200K |

## FAQ

### What is the context window of Claude Sonnet 4.5?

Claude Sonnet 4.5 has a context window of 1,000,000 tokens (1M) and can generate up to 64,000 tokens in a single response, according to models.dev.

### How much does the Claude Sonnet 4.5 API cost?

Through Claude API, Claude Sonnet 4.5 costs $3 per million input tokens and $15 per million output tokens. Prices last verified 4 Oct 2026.

### Is Claude Sonnet 4.5 open source?

No. Claude Sonnet 4.5 is a proprietary model; Anthropic has not released its weights. It is available through APIs including Claude API, Databricks, Azure AI Foundry, Vertex AI (Claude).

### When was Claude Sonnet 4.5 released?

Anthropic released Claude Sonnet 4.5 on 29 Sept 2025, according to models.dev.

### Which providers offer Claude Sonnet 4.5?

We track Claude Sonnet 4.5 on 9 providers: Claude API, Databricks, Azure AI Foundry, Vertex AI (Claude), Amazon Bedrock, Google Vertex AI, OpenRouter, Vercel AI Gateway, Snowflake Cortex.

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Data licensed CC BY 4.0. Cite as: AI Model Directory, "Claude Sonnet 4.5", https://www.aimodel.directory/models/claude-sonnet-4-5