Fast & Smooth Third-Party Web Fonts | Scott Jehl, Web Designer/Developer

If you’re loading fonts from a popular third party provider like Google Fonts or Typekit, the stylesheet link-based loading snippets they offer are not great from a performance perspective. Like any ordinary stylesheet, they block page rendering while they are loading, and for all that delay, the CSS you get merely contains font-face definitions for fonts that may be subsequently downloaded if they’re used in that page. These steps add up and can make it hard to keep sites rendering quickly.

Source: Fast & Smooth Third-Party Web Fonts | Scott Jehl, Web Designer/Developer