WhatRuns

WhatRuns is a free browser extension that lets you discover the technologies powering any website you visit. With a single click, it reveals the content management systems, frameworks, analytics tools, plugins, fonts, and web applications that a site uses. This gives you immediate insight into the technical foundation of any online property, from small blogs to enterprise websites.

The extension works by scanning the website's code and network requests to identify technology signatures. WhatRuns maintains a constantly updated database, adding 50-100 new web applications daily, ensuring it can detect both established and emerging technologies. A unique feature is the ability to follow websites and receive notifications when they start or stop using specific technologies, helping users stay informed about competitors' tech stack changes.

Web developers and digital marketers benefit most from WhatRuns. Developers can research tools and plugins for their own projects, while marketers can analyze competitor strategies by understanding their technology choices. The tool requires no registration and is completely free, making it accessible for anyone curious about website infrastructure.