Sonnet 4.6 becomes Claude’s default on Free and Pro plans

Anthropic released Sonnet 4.6 on 17 February and made it the default in Claude and Cowork for Free and Pro users. The company’s announcement described upgrades to coding, computer use, planning and document work, alongside a million-token context window in beta. Availability and the beta feature are separate claims; the larger window should not be assumed to apply to every interface or plan.

The announced starting API prices remained $3 per million input tokens and $15 per million output tokens, matching Sonnet 4.5. Anthropic also listed access through Claude Code, its API and major cloud platforms. The default-model change was the practical news for existing users: trying the new model did not require choosing the flagship Opus tier. Anthropic’s performance comparisons remained vendor evaluations. They were not a substitute for testing a specific workload, especially where tool permissions, context limits or output quality could change the result.