What is a User-Agent?
A user-agent is a string of text, numbers, and symbols that contains the details of the browser accessing a website. A user-agent will typically include the details of the device, the browser, the version of the browser, and the rendering engine you’re using to access the site.
For example, the below string is a user-agent.
User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/89.0.4389.82 Safari/537.36
From this user-agent, we can deduce that:
- The name of the browser is Google Chrome
- The version number of the browser is 89.0.4389.82
- The browser is installed on a device running the Windows 10 operating system
- The browser uses the AppleWebKit/537.36 and KHTML, like Gecko rendering engines
- The browser includes components from Safari/537.36