Change Class of HTML Tag Using JavaScript

In this tutorial we will see how to Change Class of HTML Tag Using JavaScript. The getElementById() Method and HTML DOM className Property are used for this purpose.


HTML Code is given below, This code contains a paragraph element and a button element.

<!DOCTYPE html>
<html lang="en">
<meta charset="utf-8">
<title>Change Class of HTML Tag Using JavaScript</title>  
<p id='main' class='one'>Change my Class using JavaScript</p>
<button onclick="changeClass()">Change Class</button>  

getElementById() Method

The getElementById() Method is used to get or select or target the HTML element with a specified value of Id attribute.

In this example the id of paragraph element is 'main'. This id is used to target or select the paragraph element.

getElementById() Method is supported by all major browsers.

className Property

The JavaScript className Property sets or returns the class name of an element.

The JavaScript className Property is supported by all major browsers.

JavaScript Code

In this example getElementById method is used to select the paragraph tag. Then className property is used to change the class of the paragraph tag.

onclick event is used to trigger the main function (changeClass()) which performs this task.

Take a look at the code given below.

function changeClass()
document.getElementById("main").className = "two";


Video Tutorial

Watch video tutorial on how to Change Class of HTML Tag Using JavaScript.

Password Show Hide with Eye Icon using JavaScript Change Background Color using Dropdown menu with JavaScript Get Select Tag value onchange in JavaScript Check If Class Exists JavaScript Add Event Listener To all Elements of Class JavaScript getElementsByTagName Event Listener JavaScript Change type attribute of Input Element With JavaScript Password Hide and Show with Toggle Emoji Button using JavaScript Hide and Show Navbar On Scroll With JavaScript Empty an Array in JavaScript Get Last Element Of Array Without Removing It Remove Last Element From Array JavaScript Remove First Element From Array in JavaScript Tic Tac Toe Game in JavaScript Remove Class from HTML Tag OnClick JavaScript JavaScript Select li Tag By Index Display JavaScript Variable In HTML Insert HTML Code anywhere With JavaScript JavaScript Date Difference in Days JavaScript Hide Button After Click Simple Click and Hold Effect Using JavaScript Remove Class From All Elements in JavaScript JavaScript Select All HTML Elements Whose ID Start With Same String