What Is Eager Loading?

Date First Published: 21st February 2023

Topic: Web Design & Development

Subtopic: Web Design

Article Type: Computer Terms & Definitions

Difficulty: Medium

Difficulty Level: 5/10

CONTENTS

Advantages and Disadvantages Of Eager Loading

Learn more about what eager loading is in this article.

Eager loading is the default functionality that displays all the resources of a webpage, such as images and videos onto the page at once, even if the visitor does not interact with them in a way that they are needed, such as by scrolling past them. All the required content is loaded at the same time and the browser will then store the elements in the cache so that they load more quickly for future requests. It is the opposite of lazy loading.

Most webpages use eager loading. For example, the homepage, topic pages, and subtopic pages on this website all use eager loading to load all the text and images. Wikipedia also uses eager loading as their pages mostly consist of text and a few images.

Note:

It is called eager loading as web browsers are eager to load all the elements without delaying loading until needed, unlike lazy loading.

Advantages and Disadvantages Of Eager Loading

The advantages of eager loading are:

Since all the resources load at once, users won't have to wait a while for elements below the fold to load.
Unlike lazy loading, it doesn't require any extra code for the browser to process and render. If a page has lightweight elements, eager loading is a good option as it can save time by not instructing the browser to process lots of JavaScript code.
Since no content is hidden, it is better for SEO as all content on the page will be indexed.

The disadvantages of eager loading are:

It leads to slower page loading times. Since all resources above the fold and below the fold are loaded at once, this will increase the page loading time. As a result, pages with large numbers of elements may cause browsers to crash, which will harm the user experience.
Unnecessary content can be loaded. For example, if a webpage loads 7 images below the fold and the user leaves before viewing them, the bandwidth used to provide the images would be wasted.
Since more resources are loaded at once, it will use up much more power. This will use up much more battery life on smartphones, tablets, and laptops.