Anthropic launches Claude Sonnet 5.5 with significantly lower task costs

Anthropic has released Claude Sonnet 5.5, a mid-tier model below Opus 5.5 for professional work, coding, documents, spreadsheets, presentations, and other well-scoped tasks. The company says it is more than 30% faster than Sonnet 5 and can cost up to 30% less per completed task by using fewer tokens, steps, and tool calls.

Performance gains are substantial across several benchmarks. Sonnet 5.5 scored 70.6% on TerminalBench 4.0, up from 10.3% for Sonnet 5, and reached 55.5% on CursorBench 4.0, compared with 34.1% for Sonnet 5 and 57.8% for Opus 5.5. It also nearly matched Opus on professional and computer-use tasks, scoring 1844 versus 1846 on GDPval AA and 80.1% versus 81.8% on OSWorld 2.1.

API pricing is $2 per million input tokens and $10 per million output tokens, with cache reads at $0.20 and cache writes at $2.50. These standard rates match OpenAI's GPT 6 Sol and are half the price of Opus 5.5, which costs $4 for input and $20 for output. Sonnet 5.5 is available through Claude apps and the API, as well as AWS, Google Cloud, and Microsoft Azure, while Anthropic says the lower-cost Haiku 5.5 will arrive in the coming weeks.