4

You can determine if specific a font is installed or not by checking if text in that font has a different size than normal text (source).

But panopticlick.eff.org seems to be getting my complete list, are they just checking every they know of? I can't see that info in the HTTP Request, is there just something in the DOM I can query for a list of available fonts?

Dave
  • 917
  • 1
  • 8
  • 20

1 Answers1

4

Panopticlick uses Flash to retrieve the list of fonts installed on the client's computer.

In ActionScript:

var installedFonts = TextField.getFontList();
getURL('javascript:flashFontList("' + escape(installedFonts) + '")', '_self');
Andrew Moore
  • 93,497
  • 30
  • 163
  • 175
  • @Dave: I wouldn't consider that cheating. For their purposes, it's a perfectly valid way. – Andrew Moore Mar 10 '11 at 19:03
  • 1
    I mean cheating with a :), it looks like there's a free tool for the rest of us to use too: https://github.com/gabriel/font-detect-js – Dave Mar 10 '11 at 19:09