A user agent is a string that a web browser or other client software sends to a web server with each request. It identifies the browser, operating system, and sometimes additional details about the client device. This information helps the server deliver appropriate content or features tailored to the client.
This XML form is used by user agent switcher extensions. These extensions allow users to change their browser's user agent string to mimic different browsers or devices. This can be useful for testing how websites render and behave across different browsers and devices.
A tool like this is helpful for web developers, QA testers, and anyone involved in web development or testing. It allows them to ensure their websites function correctly across a variety of user agents, helping to identify and fix compatibility issues.
You can get lists of user agent strings from various websites such as: