HTML onunload Event Attribute - HTML Window Event Attributes

The onunload event attribute in HTML allows the execution of a JavaScript script when a document is being unloaded. This event occurs in various scenarios, including:

Example of HTML onunload Event Attribute

Here executes a JavaScript when a user unloads the document.

index.html

Example: HTML

<!DOCTYPE html>
<html>
<body onunload="myFunction()">

<h1>Welcome to my Home Page</h1>

<p>Close this window or press F5 to reload the page.</p>
<p><strong>Note:</strong> Due to different browser settings, this event may not always work as expected.</p>

<script>
function myFunction() {
  alert("Thank you for visiting W3Schools!");
}
</script>

</body>
</html>

Output should be:

Definition and Usage of HTML onunload Event Attribute

The onunload attribute fires once a page has unloaded (or the browser window has been closed).

onunload occurs when the user navigates away from the page (by clicking on a link, submitting a form, closing the browser window, etc.)

Note: If you reload a page, you will also trigger the onunload event (and the onload event).

Browser Support of HTML onunload Event Attribute

Note: Due to different browser settings, this event may not always work as expected.

Syntax of HTML onunload Event Attribute

<element onunload="script">

Attribute Values of HTML onunload Event Attribute

Value	Description
script	The script to be run on onunload

How to execute a JavaScript when a user unloads the document

Close this window or press F5 to reload the page.

Note: Due to different browser settings, this event may not always work as expected

index.html

Example: HTML

<!DOCTYPE html>
<html>
<body onunload="myFunction()">

<h1>Welcome to my Home Page</h1>

<p>Close this window or press F5 to reload the page.</p>
<p><strong>Note:</strong> Due to different browser settings, this event may not always work as expected.</p>

<script>
function myFunction() {
  alert("Thank you for visiting W3Schools!");
}
</script>

</body>
</html>

Output should be:

html event attributes

Type:	Develop
Category:	Web Tutorial
Sub Category:	HTML Window Event Attributes
Uploaded by:	Admin

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