Displays the size (in px), font-family (the one chosen by Firefox from the font-family listing), font-style, font-weight, and font-variant of selected text in the context menu. Also displays the downloadable font files for the font if specified by a @font-face rule.
Does not support downloading fonts from data urls. Font providers like Typekit use data urls to obfuscate copyrighted fonts. Unfortunately, some websites may also use data urls for free fonts. And not every font provided by a downloadable file is unlicensed or free, so make sure the font you have isn't licensed before using.