WhatFont is a chrome extension (also for Safari) which can be use to identify the font family being used on any site. In addition the extension shows font-size, color and the font rendering service too.
Till today you might have been using Firebug or Chrome developer tools to identify fonts. That’s a bit, I repeat only a bit lengthy process.
WhatFont is chrome plugin (extension) that does the same job but with much more ease. You activate WhatFont in the tab and hover on a text you want to know the font of. It displays in pop up instantly. It is that easy to use.
+ In addition when you click on the text, it displays a bunch of additional information too. Like font being served by service (typekit, Google Web fonts,etc), line height and font size and the color. You can even tweet this information.