Archive: July 31st, 2014
Scott shares the code that Filament Group are using to determine which style declarations are critical (and can be inlined) and which are non-critical (and can be loaded asynchronously). It makes quite a difference in perceived performance.
By the way, I really, really like the terminology of “critical” and “non-critical” CSS, rather than “above the fold” and “below the fold” CSS.
Dave wanted to figure out if having a responsive site necessarily meant taking a performance hit, so he ran the numbers on his own site. It turns out all of performance-related issues are not related to responsive design.