WhatFont is a handy Web browser add-on for identifying webfonts. Installing WhatFont is as easy as dragging a bookmarklet to your Web browser’s bookmark bar.
Hover over some text and WhatFont will reveal the typeface’s name, size, and color; its font family; what back-up font choices the web designers specified; and show you alphabetical upper-and lowercase examples of the font.
If the font you’ve found is a Google font or from Typekit, WhatFont will also identify the relevant webfont service. Get it at http://chengyinliu.com/whatfont.html