Claude Sonnet 5.5 is the second model in Anthropic's Claude 5.5 family. It upgrades Sonnet 5 with 30%+ higher speed and up to 30% lower task cost through fewer tokens while keeping the $2 input / $10 output pricing. It targets well-scoped coding, bug fixes, document creation, and agent workflows with a 1M context window and adaptive thinking effort controls. It is the first Sonnet to include frontier-level cyber safeguards and distillation protections.
