Anthropic releases Claude Sonnet 5.5, with model-selection and migration guide

Anthropic released Claude Sonnet 5.5, the second model in the Claude 5.5 family. It is smarter and more efficient than Sonnet 5 and 30% faster, at the same price per token. Because it needs fewer tokens to finish a task, cost drops by up to 30% for most work.

Why it matters: The post gives Sonnet 5.5's pricing, the breaking changes for migration and selection advice, so you can judge whether to switch models.