Anthropic Releases Claude Sonnet 5.5: Same Price as Sonnet 5, Faster and Cheaper per Task

Anthropic released Claude Sonnet 5.5 on September 28, 2026, describing it as a significantly cheaper, faster work partner.

Pricing Unchanged

Sonnet 5.5 keeps Sonnet 5's prices: $2 per million input tokens and $10 per million output tokens. Cache reads cost $0.20 per million tokens and cache writes $2.50.

Faster, and Cheaper per Task

Anthropic says Sonnet 5.5 generates output more than 30% faster and, in its testing, costs up to 30% less per task — the savings coming from finishing work with fewer tokens rather than from a lower list price.

A Complement to Opus 5.5

Sonnet 5.5 arrived six days after Opus 5.5 and is positioned as the faster, lower-cost option alongside it. It is available on the Claude Platform, AWS, Google Cloud and Microsoft Azure.

Measure Cost per Task, Not per Token

When a model completes the same job in fewer tokens, the bill drops even if the price sheet doesn't. Teams comparing models should benchmark on their own real tasks and track total cost per completed task.