Speeding up Web Page Loading

Introduction

Before a user can consume any content, many steps are involved (for example, sending a request, getting a response, rendering the page, and so on) that can add substantial latency. There is another user-perceived delay that surfaces because of the web page construction, called a web page load delay.

A web page consists of multiple web objects, such as HTML, JavaScript, CSS, images, audio, and so on. But some web objects are not required at the initial loading of the page. For example, a web page displays the notification icon but not the list of notifications. The list can be fetched from the server only when the user clicks on the notification icon. To implement such behavior, the code used for the notification list will not be loaded initially. We want to avoid loading this code because it will increase the initial page load time (PLT). This inevitably increases the risk of users losing interest in the site and moving on to another website that loads quickly. This user behavior is depicted in the following illustration, where 2 seconds is an example of the load time: