@font-face is causing slow load times

Question

Lately i started noticing the website loads very slow at some point.

I've investigated this with firebug and when the page takes very long to load this is showing up:

It seems totally random, but the requests to webfont.woff just waits and waits forever. If i try to reach this resourse manually, it works fine and responses within 100ms. The page i'm talking about is http://wtf.maikelzweerink.nl, and the custom fonts come from the main domain maikelzweerink.nl.

The face-fonts are declared at default.css, also from the main domain:

@font-face {
    font-family: 'Proximanova Regular';
    src: url('//maikelzweerink.nl/general/font/Proximanova-Regular/webfont.eot');
    src: url('//maikelzweerink.nl/general/font/Proximanova-Regular/webfont.eot?#iefix') format('embedded-opentype'),
         url('//maikelzweerink.nl/general/font/Proximanova-Regular/webfont.woff') format('woff'),
         url('//maikelzweerink.nl/general/font/Proximanova-Regular/webfont.ttf') format('truetype'),
         url('//maikelzweerink.nl/general/font/Proximanova-Regular/webfont.svg#ProximaNovaRgRegular') format('svg');
}

Even with the correct HTTP headers

In chrome the same deal (click for larger):

Answer 1

The MIME types are set to text/plain on the fonts, rather than what they should be.

In your .htaccess file (assuming Apache), add:

AddType application/vnd.ms-fontobject  eot
AddType application/x-font-ttf         ttf ttc
AddType font/opentype                  otf
AddType application/x-font-woff        woff

This will fix things, and make sure the fonts work in all browsers.