Library Detector is a Chrome add-on developed by aaronxyliu. It is a free tool that allows users to detect JavaScript libraries used on the current web page. This tool is supported by academic software engineering researches and is designed to accurately detect libraries running on the web.

With Library Detector, users can pinpoint the version of the library being used and even reveal libraries that may be hidden by web packers or obfuscators. Using the tool is simple - just open a website, click on the extension icon (which needs to be pinned in the extension bar in advance), and click on the "detect" button in the popup menu. The tool will then display all the libraries loaded by the website.