I just tried to use Google Fonts and have noticed the following disturbing effect:
The result of using the font at my custom html file is different from what's present on Google site.
At least the font size is definitely different (color is also different, but it doesn't matter).
Font: Slabo 27px, size: 112px
Link to the Google Fonts: https://fonts.google.com/specimen/Slabo+27px
The browser is the same: Firefox.
At my site
HTLM code that I used:
<link rel="stylesheet" href="css/main.css">
<link rel="stylesheet" href="https://fonts.googleapis.com/css?family=Slabo+27px">
font-family: 'Slabo 27px';
same, don't see difference, both have size 112px. https://jsfiddle.net/fp9j7L85/
<link href="https://fonts.googleapis.com/css?family=Slabo+27px" rel="stylesheet">