Source-backed update · October 2026
Anthropic introduces Claude Sonnet 5.5
Anthropic positions Sonnet 5.5 for scoped daily work; task cost still depends on usage.
Announcement: Published: Sources checked: 9 October 2026
What was announced
Anthropic announced Sonnet 5.5 on 28 September. The release describes a model for scoped everyday work, including bug fixes and document creation. It distinguishes the token list price from its claimed lower cost to complete typical tasks. Those savings depend on the vendor’s workload and settings. A later Haiku announcement changes Sonnet cache-read pricing, so the launch page alone is not a current billing quote. Use the live pricing documentation when estimating a new application.
Before adopting it
A model evaluation should include output acceptance, human review time, retries and the full billed token mix.