A browser sends User Agent to web server in a HTTP header whenever you connect to a website with the browser, rendering engine and operating system identifiable information, in return web server serves different pages to different browsers and different Operating systems.
I. In Edge browser: Visit any website, press F12 to open Developer tools or click on More actions and select ‘F12 Developer Tools’
Paste the below code and press enter
II. In Internet Explorer: Press F12 to open Developer Tools
Click on Console, paste the command and press enter to run.
III. In Chrome, Press Ctrl+Shift+I to open developer tools, or you can open DT from menu > More Tools > Developer Tools
Press Ctrl+V and enter.
IV. In Firefox, open Web Console by using Ctrl+Shift+k shortcut or click on menu > Developer, select Web Console