Anthropic: Claude Sonnet 4.5 (20250929)
Claude Sonnet 4.5 (20250929) is a reasoning model from Anthropic released on Sep 29, 2025. It reads text, images and files and writes text, with a 200K token context window and up to 64K tokens per reply.
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It costs $3 per million input tokens and $15 per million output tokens. Cached input bills at $0.30, 90% less than fresh input.
It supports tool calling, structured JSON output and prompt caching.
8 providers serve it, including Databricks, Vertex (Anthropic) and Amazon Bedrock.
- Modalities
- In / out price
- $3 / $15 per 1M
- Context
- 200K
- Max output
- 64K
- Released
- Sep 29, 2025
- Knowledge cutoff
- Jul 2025
- Tool calling
- Structured output
- Reasoning
- Prompt caching
- Open weights
- Free to use
Claude Sonnet 4.5 (20250929) pricing
USD, as listed on Oct 19, 2026. Most bills are input heavy, so the cached input rate matters as much as the headline price.
| Input | $3 / 1M tokens | |
|---|---|---|
| Output | $15 / 1M tokens | |
| Cached input (read) | $0.30 / 1M tokens | 90% off input |
| Cache write | $3.75 / 1M tokens |
Claude Sonnet 4.5 (20250929) providers
8 providers serve it, including Databricks, Vertex (Anthropic) and Amazon Bedrock. Each host sets its own price and limits, so the cheapest one is not always the one with the longest context.
| Provider | Input /M | Output /M | Cache read /M | Context | Max output |
|---|---|---|---|---|---|
| Databricks | $3 | $15 | $0.30 | 200K | 64K |
| Vertex (Anthropic) | $3 | $15 | $0.30 | 200K | 64K |
| Amazon Bedrock | $3.30 | $16.50 | $0.33 | 200K | 64K |
| Abacus | $3 | $15 | n/a | 200K | 64K |
| DevPass (LLM Gateway) | $3 | $15 | $0.30 | 200K | 64K |
| LLM Gateway | $3 | $15 | $0.30 | 200K | 64K |
| Merge Gateway | $3 | $15 | $0.30 | 200K | 64K |
| Tempr Gateway | $3 | $15 | $0.30 | 200K | 64K |
What Claude Sonnet 4.5 (20250929) costs per month
Pick a workload close to yours or type your own volumes.
Supported request parameters
What you can set when you call Claude Sonnet 4.5 (20250929) through an OpenAI compatible API.
- Tools
tools - Structured outputs
structured_outputs - Reasoning
reasoning - Temperature
temperature
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Claude Sonnet 4.5 (20250929) questions
How much does the Claude Sonnet 4.5 (20250929) API cost?
$3 per million input tokens and $15 per million output tokens, with cached input at $0.30. The estimator on this page turns that into a monthly bill for your own workload.
What is the context window of Claude Sonnet 4.5 (20250929)?
200,000 tokens of input, and it can write up to 64,000 tokens in one reply. As a rough guide, a million tokens is around 750,000 English words.
Which providers serve Claude Sonnet 4.5 (20250929)?
8 providers serve it, including Databricks, Vertex (Anthropic) and Amazon Bedrock. Prices differ by host, so the Providers table on this page lists each one with its input and output price.
Does Claude Sonnet 4.5 (20250929) support tool calling?
Yes. It accepts tool definitions and can return JSON that matches a schema, which is what an agent needs to call your APIs.
Is Claude Sonnet 4.5 (20250929) open source?
No. Anthropic serves it through an API only, so you cannot download the weights or host it yourself.
When was Claude Sonnet 4.5 (20250929) released?
Sep 29, 2025, with training data up to Jul 2025.
Catalog data from models.dev (MIT licensed), refreshed daily, last on Oct 19, 2026. The summary is written from these facts.