The onunload event attribute works when the document is being unloaded i.e. it occurs when the browser has been closed. It is mostly used when the user opens a link and submits the form and closes the browser window. Basically, it is:
- Fired when a user navigates away from a page or closes the browser.
- Useful for executing cleanup actions or displaying confirmation prompts.
- Allows to handle scenarios before the page unloads.
Supported Tags
Syntax
<element onunload = "script">Attribute Value
This attribute contains a single value script that works when onunload event is triggered.
Example: In this example, we will see the use of onunload event attribute
<!DOCTYPE html>
<html>
<head>
<title>
HTML onunload Event Attribute
</title>
<script>
function Geeks() {
alert("onunload event attribute called");
}
</script>
</head>
<body onunload="Geeks()">
<h1>
GeeksforGeeks
</h1>
<h2>
onunload Event Attribute
</h2>
</body>
</html>
Output:
Note: This event may not work always as expected.
Supported Browsers
The browser supported by onunload event attribute are listed below :
- Google Chrome 1 and above
- Edge 12 and above
- Firefox 1 and above
- Opera 4 and above
- Safari 3 and above
