Anthropic launched Claude Sonnet 5.5 on September 28, 2026, introducing a powerful yet cost-effective AI model that closely rivals its premium counterpart, Claude Opus 5.5, released just a week earlier. The new model offers strong coding and productivity capabilities at a significantly lower price point, making it an attractive option for businesses that need reliable AI assistance without the higher expense of Opus.
Pricing and Performance
Sonnet 5.5 is priced at $2 per million input tokens and $10 per million output tokens—roughly half the cost of Opus 5.5, which charges $4 per million input tokens and $20 per million output tokens. Despite the lower price, Sonnet 5.5 is more than 30% faster than its predecessor, Sonnet 5.
Performance benchmarks show Sonnet 5.5 competing closely with Opus 5.5. It scored 70.6% on the Terminal-Bench 4.0 test, compared to 66.4% for Opus 5.5. On an independent intelligence index, the new Sonnet model achieved a score of 56, up from 38 for the previous generation. However, Anthropic notes that Opus remains the better choice for tasks requiring deeper reasoning and longer workflows.
Availability and Features
Claude Sonnet 5.5 is available now on Amazon Web Services, Google Cloud, and Microsoft Azure under the model name claude-sonnet-5-5. It offers zero data retention, and Anthropic has promised the release of Claude Haiku 5.5 in the coming weeks.
Why Cost Matters for Everyday AI Work
The lower cost of Sonnet 5.5 is especially valuable for companies that use AI extensively. Developers can leverage the model for coding, bug fixing, and code review, while business users can generate documents, slides, and spreadsheets more efficiently. With thousands of daily AI requests, even small savings per token add up significantly. Faster response times and reduced token usage further help control operational costs.
Sonnet 5.5 does not make Opus 5.5 obsolete—the two models serve different needs. Sonnet handles routine tasks at a lower cost, while Opus remains the go-to for complex, resource-intensive work. For users, the key takeaway is clear: there is now a more affordable option that covers a wide range of daily AI tasks without requiring the premium model.