Claude Sonnet 5.5 - Anthropic's second model in the Claude 5.5 family
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Claude Sonnet 5.5 is Anthropic’s fast, cost-efficient AI model for everyday work: coding, bug fixes, documents, slides, and design. It runs 30%+ faster than Sonnet 5, lowers task costs up to 30%, and delivers stronger coding and knowledge-work performance.
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Claude Sonnet 5.5 is Anthropic’s faster, more cost-efficient AI model for everyday coding and knowledge work.
It tackles slow, expensive task completion by running over 30% faster than Sonnet 5 and lowering task costs by up to 30%. It combines speed, cost efficiency, and stronger performance for coding and knowledge-work tasks.
Features & Benefits
30%+ faster than Sonnet 5
Up to 30% lower task costs
Stronger coding and knowledge-work performance
Works across code, bug fixes, documents, slides, and design
Built for users working on code, bug fixes, documents, slides, and design.
Get Started
Claude Sonnet 5.5 is now available on all platforms, including Amazon Web Services, Google Cloud, and Microsoft Azure.
Developers can get started on the Claude Platform with claude-sonnet-5-5. If you run Sonnet with thinking off, you’ll need to switch to the new between_tools setting, which keeps up-front thinking off, before moving to Sonnet 5.5.
P.S. I hunt the latest and greatest launches in tech, SaaS and AI, follow to be notified → @rohanrecommends
@rohanrecommends the speed and lower cost are what stand out to me here especially for everyday coding tasks where you run the model a lot
@rohanrecommends @shivam_kushwaha16 Totally agree. Speed and cost are the main driver
impressive, I'm a big fan of anthropic and your models, using it on a daily basis
Rohan's note about thinking settings is worth reading twice. When I moved a small agent onto Sonnet 5, responses started coming back with a thinking block first, and my code was reading content[0]. It broke.
If anything of yours reads the first block, pick the text or tool_use block by type before you change the model string.