JavaScript - Change the font size of a Element

In this tutorial, we are going to learn about how to change the font size of a html element using JavaScript.

Consider, that we have the following p element in our HTML:

<p class="content">Random text goes here</p>

Now, we want to change the above element size using JavaScript.

Changing the font size

To change the font size of a element, first we need to access the element object inside the JavaScript using the document.getElementByClassName() method.

const el = document.getElementByClassName("content");

Now, set its style.fontSize property to your desired size (eg: 10px or 20px, etc).

el.style.fontSize = "20px";

It changes the font size of a element to 20px.

Full example:

<p class="content">Random text goes here</p>

JavaScript:

const el = document.getElementByClassName("content");

el.style.fontSize = "20px"; // changes the font size