How Exactly Does link rel=”preload” Work?

When the end-user performs any operation on the website or web app, the developers sometimes want to display or execute some most important resources as early as possible without having the user to wait. More specifically, the link rel=“preload” works in such a way that it instructs the browser to load and cache certain resources as soon as possible.

Let’s discuss briefly how the rel=“preload” works.

How Exactly Does link rel=”preload” Work?

When a web page is loaded on the browser, the header is loaded first before all other elements on the web page. When the user performs an operation that has the rel=“preload” in it, the browser starts loading the resources with the rel=“preload” earlier. After loading them, the other resources are loaded. This ensures that there will be no lag in loading the resources defined in the rel=“preload”.

How to Use link rel=”preload”?

The rel=”preload” is added in the link tag. Moreover, inside the link tag, it is required to add the “rel”, “href”, and “attributes” and define their values.

Following is the syntax of adding rel=”preload” in the link tag in a document:

<link rel="preload" href="/link or file" as="browser file"/>

In the above syntax:

  • Inside the link tag, there is a “rel” attribute that is defined as “preload”.
  • After that, the “href” specifies the attribute with the resource to be preloaded (link or the file).
  • The “as” attribute contains the file that needs to be downloaded from the browser. For instance, “style”, “font”, “script”, “fetch” etc.

Example: Adding rel=”preload” in the “link” Tag
Let’s discuss how the resources are declared in the rel=“preload” function using the above syntax:

<link rel="preload" href="/style.css" as="style"/>

According to the above statement, to declare a file or resource in the rel=“preload”:

  • A link tag has been created with the rel=“preload” attribute as per the syntax.
  • Inside it, the “href” attribute with a resource file named style.css has been defined.
  • Then, the “as” attribute is the attribute specified as “style”.

Benefits of Using rel=”preload”

rel=“preload” provides the developers with the following benefits:

  • The rel=”preload” is very helpful in software where instant display or execution of some resources are required.
  • It lets the browser identify the resource type so that it can point out if the same type of resource is used in the future.
  • It saves the time of the users as they do not have to wait for minutes or seconds.
  • Its usage makes the website or web app look more reliable because slow processing is a big distraction for many users that leads the users to move to some other platform.
  • The browser can match the resources with the content security policy by the “as” attribute added in the tag.

This is all about the working and functionality of rel=”preload” in HTML.


The rel=”preload” attribute is used in HTML documents to speed up the processing of a web page by instructing the browser to load certain resources on the web page as soon as possible. Through its

About the author

Hadia Atiq

A Software Engineer and Technical Writer passionate about learning and spreading knowledge of the latest technology. I utilize my writing skills to help readers understand the importance and usage of modern technology.