High Performance Mobile Web

Chapter 6. Optimizing for the First Visit

The first visit to our website is one of most important ones in terms of performance and the conversion impact of it. The user has just typed a URL, clicked on a search result at Google, or seen an interesting tweet with a related link and she is expecting our content as soon as possible.

Failing in delivering the fastest experience at the first visit can lead to fewer conversions and more people just leaving our websites forever. We know we don’t want that, and that’s why we are now going to cover the basics of optimizing web content for the first visit.

In this chapter, we’ll focus on the main techniques that will increase performance—and the perception of it—with normal effort, such as setting up our server and understanding how the CSS and JavaScript load and block rendering.

I’m saying this because in Chapter 10 we will enter into the extreme side of web performance optimization, leading to faster websites and more conversions but with bigger efforts in terms of implementation—techniques such as using new compression algorithms or separating out the above-the-fold content while inlining everything to fit in one TCP packet.

The HTTP Side

HTTP—and HTTPS, its secure counterpart—is the protocol we are going to use by default for the initial load process when working with websites and web apps. This section is useless when talking about hybrid apps, as the initial loading of these will be based on a local filesystem, as we will cover ...