Speaker Deck

CSS and the critical path

by Patrick Hamann

Published September 28, 2013 in Technology

The perceived speed of your website relies heavily on the browser being able to paint to your user's screen. For this they must construct a "render tree" which consists of the DOM and the often forgotten CSSOM.

The critical path which the browser takes to gather this information is the only thing standing between your server and the user's screen. Using new research and real world examples, Patrick Hamann will cover a range of techniques – from the controversial to bleeding edge – the Guardian is using to make their CSS load as fast as possible, and ultimately keeping it off the critical path.