How to Check if a String is Empty or Not in Javascript

In this tutorial, you will learn how to check if a string is empty or not in javascript. A string is considered to be empty when it does not have any characters or content in it and as a result, the length of that string will always be 0.

There are certain primitive types in javascript and string is one of them. As the name suggests, any variable that holds a plain text as its value is considered to be of string type.

There are numerous ways to detect whether a string is empty or not. But for the sake of simplicity, we will use a strict equality operator (===) to accomplish our goal.

In the following example, we have one global variable that holds a string. Upon click of a button, we will check whether it is empty or not 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 “Check” and for the h1 element, it is “Result”.
  • 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 btnCheck and output variables respectively.
  • We have attached a click event listener to the button element.
  • We have a global variable myString which holds an empty string as its value.
  • In the event handler function, we are using a strict equality operator (===) to verify whether myString is empty or not. Depending upon the result of the check, we will assign “Empty” or “Not Empty” to the result variable.
  • We are displaying the result in the h1 element using the innerText property.
let btnCheck = document.querySelector("button");
let output = document.querySelector("h1");

let myString = "";

btnCheck.addEventListener("click", () => { 
  let result = myString === "" ? "Empty" : "Not Empty";
  output.innerText = result;