Offline.js automatically alerts users for their internet connection using AJAX requests.
Download offline.min.js
offline.html
<script src="offline.min.js"></script> <script> Offline.options = {checks: {xhr: {url: 'offline.html'}}}; var run = function(){ // check internet connection Offline.check(); // return internet connection state console.log(Offline.state); document.getElementById("status").innerHTML = Offline.state; } setInterval(run, 5000); </script> <div id="status">up</div>