To add a CSS class to an HTML element, you can use the classList property of the element. It is a read-only property that returns a live DOMTokenList collection of all the classes applied to the element.

Let us say you have the following HTML element:


To add the pizza class to the above <div> element, you can use the following code:

const div = document.querySelector('div');


The classList.add() method also allows you to add multiple classes:

const div = document.querySelector('div');

div.classList.add('pizza', 'spice', 'potato');

The classList property only works in modern browsers, and IE10 and above.

Take a look at this article to learn more about adding, removing, and toggling CSS classes in JavaScript.

✌️ Like this article? Follow me on Twitter and LinkedIn. You can also subscribe to RSS Feed.