# Claude Sonnet 4.5

Claude Sonnet 4.5 is a model from Anthropic, released on 29 Sep 2025. The context window is 200,000 tokens. The maximum output is 64,000 tokens. Pricing is $3.00 per million input tokens and $15.00 per million output tokens.

- Developer: Anthropic
- Id: claude-sonnet-4-5
- Reported: 2026-09-10T00:00:00.000Z
- Released: 2025-09-29T00:00:00.000Z
- Sighting: 2026-09-21T18:47:57.048Z
  - [evidence link](https://models.dev/#claude-sonnet-4-5)
- Status: Released
- Canonical: https://alexgetman.com/models/anthropic/claude-sonnet-4-5/

## Questions

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

The context window is 200,000 tokens. The maximum output is 64,000 tokens.

### How much does Claude Sonnet 4.5 cost?

Pricing is $3.00 per million input tokens and $15.00 per million output tokens. Cached input is $0.30 per million.

### When was Claude Sonnet 4.5 released?

On 29 Sep 2025.

## Timeline

- 2026-11-13T20:01:49.880Z · [Anthropic · official articles](https://www.anthropic.com/threat-intelligence-report-september-2026)

## Evidence links

- [Vertex AI · Model Garden](https://console.cloud.google.com/vertex-ai/publishers/anthropic/model-garden/claude-sonnet-4-5)
- [AWS Bedrock · lifecycle](https://docs.aws.amazon.com/en_en/bedrock/latest/userguide/model-lifecycle-legacy.html)
- [Azure Foundry · lifecycle](https://learn.microsoft.com/en-us/azure/foundry/concepts/model-lifecycle-retirement?view=azureml-api-2)
- [models.dev · catalogue](https://models.dev/#anthropic--claude-4.5-sonnet)
- [models-dev](https://models.dev/#claude-sonnet-4-5)
- [models.dev · catalogue](https://models.dev/#claude-sonnet-4.5)
- [models.dev · catalogue](https://models.dev/#databricks-claude-sonnet-4-5)
- [OpenCode · discovery](https://opencode.ai/data/anthropic/claude-sonnet-4-5)
- [anthropic-pricing](https://platform.claude.com/docs/en/about-claude/pricing)
- [review](https://platform.claude.com/docs/en/models/sonnet-4-5/overview)
- [Vercel AI Gateway](https://vercel.com/ai-gateway)
- [VoxelBench · leaderboard](https://voxelbench.ai/leaderboard)
- [Arena · leaderboards](https://www.anthropic.com/news/claude-sonnet-4-5)
- [anthropic-articles](https://www.anthropic.com/threat-intelligence-report-september-2026)

## Signals

- [Claude Sonnet 4.5 spotted on VoxelBench](https://alexgetman.com/signals/2026/09/14/claude-sonnet-4-5-32k-thinking/)