For this, you need to have the browser extension, WhatFont, installed and enabled. You can download it for free from the Play Store for Chrome or the App Store for Safari. If you prefer to use Firefox, you can get the bookmarklet to easily use WhatFont. This is not the same extension as WhatTheFont or MyFonts.

You can click that font for more details, like the size, font family, and style. WhatFont does not work on every site! If you instead get a drop-down menu when you click the extension icon, you can go to the WhatFont site, but the extension isn’t working for that page. You can wait a minute for the information to load and then try again, but some sites just won’t work with it. If WhatFont isn’t working for you, try Fontanello, which works for Chrome, and Firefox. To use Fontanello, highlight the text, right-click it, then select Fontanello to see information about that font.