HTML DOM onoffline Event

Last Updated : 15 Jun, 2023

The DOM onoffline event occurs on offline work of the browser. The onoffline event is a conflict with the ononline event.

Note: navigator.onLine property is used to check the mode of the browser.

Supported Tags:

<body>

Syntax:

In HTML:

<element onoffline="myScript">

In JavaScript:

object.onoffline = function(){myScript};

In JavaScript, using the addEventListener() method:

object.addEventListener("offline", myScript);

Example: Using the addEventListener() method

HTML

<!DOCTYPE html>
<html>
   
<head>
    <title>
        HTML DOM onoffline Event
    </title>
</head>
 
<body>
    <h1>
        GeeksforGeeks
    </h1>
    <h2>
        HTML DOM onoffline Event
    </h2>
   
    <script>
        window.addEventListener("online", onlineGFG);
        window.addEventListener("offline", offlineGFG);
        function onlineGFG() {
            alert("Online");
        }
        function offlineGFG() {
            alert("Offline");
        }
    </script>
</body>
   
</html>