Above-the-fold optimization & content prioritization
Optimizing the first page load for the speediest above-the-fold render time is one of the tricks that great websites use to deliver a snappy user experience. In short, optimizing for this boils down to making sure that only assets that are important related to rendering the first view are send down the wire, and inlining as much of these assets that actually are needed as possible.
Prioritize Critical CSS
This optimization determines which CSS rules are needed for rendering what is above-the-fold for the current browser, and inlines just that into the top of the page.
This optimization determines which images are visible above the fold for the current user agent, and inlines those that qualify.
With above-the-fold content priorotization optimizations, you site should feel a *lot* snapper. Especially mobile user-agents and large pages will benefit. It is good to have a look at the other PageSpeed optimizations as well. For example, a DSN lookup can take seconds on a 3g connection - our filter that inserts dns prefetch hints can really make a huge difference here.
Automating content prioritization and first page load optimization: