Claude Sonnet 5
Claude Sonnet 5 is an active earlier Sonnet release with adaptive thinking. Its request controls differ from older models that accepted sampling settings.
Older request defaults can cause errors
The temperature, top_p and top_k fields return a 400 error. Integrations must omit them rather than reuse an earlier model’s request object. Reasoning effort is a separate control. The model supports the batch-only extended output option without changing the ordinary 128,000-token limit.Claude Sonnet 5 model reference
Specifications & access
| Detail | Value and conditions |
|---|---|
| Launch date | |
| Access | API |
| Model identifiers | claude-sonnet-5 |
| Context window | 1,000,000 tokens Direct Claude API context limit Claude Sonnet 5 model reference |
| Maximum output | 128,000 tokens Synchronous Messages API maximum Claude Sonnet 5 model reference |
| Maximum output | 300,000 tokens Message Batches only, with output-300k-2026-03-24 beta header Claude Sonnet 5 model reference |
| Input price | 2 USD per million tokens Standard direct API input; cache, batch and tool charges are separate Claude Sonnet 5 model reference |
| Output price | 10 USD per million tokens Standard direct API output Claude Sonnet 5 model reference |
| Input and output | Text and images in; text outClaude Sonnet 5 model reference |
| Reasoning control | Adaptive thinking; default effort is high.Claude Sonnet 5 model reference |
| Reliable knowledge cutoff | January 2026Claude Sonnet 5 model reference |
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Launch date API - Claude Sonnet 4.6
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Claude Sonnet 4.6 remains active with a one-million-token context and adaptive thinking.
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