HTML Navigator onLine Property

The HTML navigator onLine property returns a boolean value that defines whether the browser is online or offline.


Following is the syntax −


Let us see an example of HTML navigator onLine property −


 Live Demo

<!DOCTYPE html>
   body {
      color: #000;
      height: 100vh;
      background: linear-gradient(62deg, #FBAB7E 0%, #F7CE68 100%) no-repeat;
      text-align: center;
   .btn {
      background: #db133a;
      border: none;
      height: 2rem;
      border-radius: 20px;
      width: 330px;
      display: block;
      color: #fff;
      outline: none;
      cursor: pointer;
      margin: 1rem auto;
   .show {
      font-size: 1.2rem;
      color: #fff;
<h1>HTML navigator onLine property Demo</h1>
<button class="btn" onclick="display()">Check Browser Online/Offline Mode</button>
<div class="show"></div>
   function display() {
      var msg = document.querySelector(".show");
      if (navigator.onLine) {
         msg.innerHTML = "Hey! You are online";
      } else {
         msg.innerHTML = "Hey! You are offline";


Click on “Check Browser Online/Offline Mode” button to whether the browser is in online or offline mode −

Now try to disconnect your network and then click again on “Check Browser Online/Offline Mode” button −