Claude Sonnet 4.5
Claude Sonnet 4.5 is deprecated and scheduled to retire from Anthropic-operated platforms on 30 November 2026. Existing integrations should use the current migration guidance.
Deprecated API; check access details
Deprecated does not yet mean retired
The model is still functional on the review date, but Anthropic no longer recommends it. Its documented replacement is Sonnet 5.5. This record preserves the exact API identifier and limits so users can identify an older integration without mistaking it for a new-model recommendation.Claude Sonnet 4.5 model reference
Specifications & access
| Detail | Value and conditions |
|---|---|
| Status | Deprecated API; check access details |
| Launch date | |
| Access | API |
| Model identifiers | claude-sonnet-4-5-20250929claude-sonnet-4-5 |
| Context window | 200,000 tokens Direct Claude API context limit Claude Sonnet 4.5 model reference |
| Maximum output | 64,000 tokens Synchronous Messages API maximum Claude Sonnet 4.5 model reference |
| Input price | 3 USD per million tokens Standard direct API input; cache, batch and tool charges are separate Claude Sonnet 4.5 model reference |
| Output price | 15 USD per million tokens Standard direct API output Claude Sonnet 4.5 model reference |
| Input and output | Text and images in; text outClaude Sonnet 4.5 model reference |
| Reasoning control | Manual extended thinking; effort control is not supported.Claude Sonnet 4.5 model reference |
| Reliable knowledge cutoff | January 2025Claude Sonnet 4.5 model reference |
Related models
- Claude Sonnet 5.5
Anthropic · Claude Sonnet
A model for coding, writing and agent tasks with configurable reasoning.
Launch date API - Claude Sonnet 4.6
Anthropic · Claude Sonnet
Claude Sonnet 4.6 remains active with a one-million-token context and adaptive thinking.
Launch date API