There are several hacks. Almost all of them rely on using JavaScript to make a XMLHttpRequest to retrieve font data. This will force the browser to load the fonts earlier by working around the normal @font-face loading mechanism.

Because you already have the font data in JavaScript you can then also store the fonts in localStorage. This way you can avoid making a request for them on the next page load.

Smashing Magazine wrote a bit more about this technique: http://www.smashingmagazine.com/2014/09/improving-smashing-m...

I'm generally against this idea because you're basically reimplementing the browsers' caching mechanism. The CSS Font Loading API (http://www.w3.org/TR/css-font-loading/) will let you do this in a much nicer way and it already has pretty decent browser support (Chrome, Opera and Firefox beta).