How to Replace Space with %20 in Javascript

In this tutorial, you will learn how to replace space with %20 in javascript. Words in a sentence are separated from each other with the help of a space. By having a space, not only the words but the entire sentence becomes meaningful. In case of URLs, the space is encoded as %20.

There are numerous ways to replace the space with %20. We are going to use the simplest approach which involves the usage of the encodeURIComponent() and trim() methods. The trim() method will remove any extra space at the beginning as well as at the end of the string. The encodeURIComponent() method will replace certain characters in a string by one, two, three, or four escape sequences representing the UTF-8 encoding of the character.

In the following example, we have one global variable that holds a string. Upon click of a button, we will replace the space with %20 and display the result on the screen.  Please have a look over the code example and the steps given below.


  • We have 3 elements in the HTML file (div, button, and h1). The div element is just a wrapper for the rest of the elements.
  • The innerText for the button element is “Replace”.
  • We have done some basic styling using CSS and added the link to our style.css stylesheet inside the head element.
  • We have also included our javascript file script.js with a script tag at the bottom.
<!DOCTYPE html>
<html lang="en">

  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <meta http-equiv="X-UA-Compatible" content="ie=edge">
  <link rel="stylesheet" href="style.css">


  <div class="container">    

  <script src="script.js"></script>

.container {        
    text-align: center;

button {
  margin-top: 10px;
  padding: 10px 20px;


  • We have selected the button element and h1 element using the document.querySelector() method and stored them in btnReplace and output variables respectively.
  • We have attached a click event listener to the button element.
  • We have a global variable myString which holds a string as its value.
  • We are displaying the original string in the h1 element using the innerText property.
  • In the event handler function, we are calling the trim() method to get rid of any extra space at the beginning as well as at the end of the string.
  • We are calling the encodeURIComponent() method and passing the string returned by the trim() method as a parameter. As a result, it will replace all occurrences of space with %20. The new string returned by this method will be stored in the result variable.
  • We are displaying the result in the h1 element using the innerText property.
let btnReplace = document.querySelector("button");
let output = document.querySelector("h1");

let myString = " page";

output.innerText = myString;

btnReplace.addEventListener("click", () => {  
  let result = encodeURIComponent(myString.trim());
  output.innerText = result;