Earlier this month we covered Google’s revamp of their pagespeed insights tool, where they greatly improve the usability and details within the tool itself.

Last night, Google announced this new tool on the webmaster blog and added new mobile guidelines for your web sites.

In short, Google wants your mobile pages to render really fast – not like the common page that takes 7 seconds to load but more like them rendering in a sub-second. Google is giving you advice on how to achieve that and then providing benchmarking testing tools to help you get there.

Google does clarify that the content above the fold is the main thing that should render immediately. And there are techniques to load such content first. The other best practices include:

Server must render the response (< 200 ms)
Number of redirects should be minimized
Number of roundtrips to first render should be minimized
Avoid external blocking JavaScript and CSS in above-the-fold content
Reserve time for browser layout and rendering (200 ms)
Optimize JavaScript execution and rendering time

Pierre Far, from Google adds a lot more detail in human english on his Google+ page:

Forum discussion at Google+.