Anthropic: Claude Sonnet Latest

This model always redirects to the latest model in the Claude Sonnet family.

The Claude Sonnet Latest documentation on OpenRouter includes the Claude 5.5 Migration Guide cookbook. The quickstart covers API keys and your first request, and the API reference lists every parameter.

Claude Sonnet Latest has no fixed price of its own. Each request is billed at the price of the model that serves it, so your cost depends on which model the request is routed to.

Claude Sonnet Latest can route to models with context windows of up to 1,000,000 tokens. The context length available to a request is that of the model that serves it.

Claude Sonnet Latest accepts text, images, and files such as PDFs as input and returns text.

Claude Fable 5.2, Claude Haiku 5.5, Claude Opus 5.5 and 12 more are other text models from Anthropic.

Claude Sonnet Latest was released on April 27, 2026.