HTML onunload Event Attribute - 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:

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Single Articles

Example of HTML onunload Event Attribute	Window Event Attributes
Definition and Usage of HTML onunload Event Attribute	Window Event Attributes
Browser Support of HTML onunload Event Attribute	Window Event Attributes
Syntax of HTML onunload Event Attribute	Window Event Attributes
Attribute Values of HTML onunload Event Attribute	Window Event Attributes
How to execute a JavaScript when a user unloads the document	Window Event Attributes

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

Reffered: https://www.w3schools.com/tags/ev_onunload.asp