A practical guide to what changed, the benchmarks that matter, the cost controls developers should not miss, and one hands-on demo worth building.\u00a0<\/p>\n
\nAnthropic has just released Claude Sonnet 5.5<\/u>.\n<\/p>\n
It is the middle child of the Claude family, and the one most people will actually use. It is quick, capable, cheap to run, and free to use for all users<\/mark> without any subscription.\u00a0<\/p>\n In this article, we go over the latest iteration of the Claude\u2019s Sonnet family. We put it to test to see whether its agentic claims had any truth to them or not. And how a regular user of Claude app benefit with this free upgrade.\u00a0<\/p>\n Sonnet 5.5 is now the default model for all users of Claude App. If you use Claude without a subscription, this is the model you are talking to. Opus 5.5 stays behind a paid plan, so for most people, Sonnet 5.5 is simply what Claude is. In short, the following improvements have been made:\u00a0<\/p>\n Why this release matters <\/strong>Sonnet 5.5 is not a replacement for Opus 5.5 on the hardest open-ended work. It is the model to look at when the task is well-scoped, repeatable, tool-heavy, or latency-sensitive.\u00a0<\/p>\n Anthropic positions Sonnet 5.5 as a fast low-cost <\/em>complement to Opus 5.5. In the Claude apps, Medium effort is the default. On the Claude Platform, High is the default. That difference matters because effort changes latency, token use, and how much the model verifies its own work.\u00a0<\/p>\n Anthropic does not publish Sonnet 5.5 parameter count, layer count, mixture-of-experts layout, or other internal model architecture details\u2026 which is expected for any proprietary model. Any article that gives those numbers is speculating. Its key features, are out in the open though:\u00a0<\/p>\n For technical leaders, this is a useful architecture view: input context, reasoning budget, tool loop, verification behavior, and output. Those are the levers that determine reliability and cost in production.\u00a0<\/p>\n One of the biggest advantages of Sonnet 5.5 is that you don\u2019t need a paid Claude subscription to try it<\/strong>. You can access the model through Claude\u2019s free tier, although free users have usage limits that reset every five hours.\u00a0<\/p>\nWhat\u2019s new in Sonnet 5.5?<\/h2>\n
![\"Sonnet](\"https:\/\/cdn.analyticsvidhya.com\/wp-content\/uploads\/2026\/09\/image6-13.png\")
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![\"Pricing](\"https:\/\/cdn.analyticsvidhya.com\/wp-content\/uploads\/2026\/09\/image7-11.png\")
<\/figure>\n<\/div>\nClaude Sonnet 5.5 Features<\/h2>\n
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low<\/code>, medium<\/code>, high<\/code>, xhigh<\/code>, and max<\/code>. Adaptive thinking makes it so that you can\u2019t disable effort\/reasoning. \u00a0<\/li>\nHow to Access Claude Sonnet 5.5?<\/h2>\n
![\"Sonnet](\"https:\/\/cdn.analyticsvidhya.com\/wp-content\/uploads\/2026\/09\/image8-12-scaled.png\")
<\/figure>\n<\/div>\n![\"Dashboard](\"https:\/\/cdn.analyticsvidhya.com\/wp-content\/uploads\/2026\/09\/brrgangn.png\")
<\/figure>\n<\/div>\n![\"Fixed](\"https:\/\/cdn.analyticsvidhya.com\/wp-content\/uploads\/2026\/09\/image-1-1-scaled.png\")
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