WindowEventHandlers.onunload

The unload event is raised when the window is unloading its content and resources. The resources removal is processed after the unload event occurs.

Syntax

window.onunload = funcRef;

• funcRef is a reference to a function.

Notes

Using this event handler in your page prevents Firefox 1.5 from caching the page in the in-memory bfcache. See Using Firefox 1.5 caching for details.

Browsers equipped with pop-up window blockers will ignore all window.open() method calls in onunload event handler functions.

You can and should handle this event through window.addEventListener() and the unload event. More documentation is available there.

Specifications

Specification	Status	Comment
WHATWG HTML Living Standard The definition of 'GlobalEventHandlers' in that specification.	Living Standard
HTML5.1 The definition of 'GlobalEventHandlers' in that specification.	Recommendation
HTML5 The definition of 'GlobalEventHandlers' in that specification.	Recommendation

Browser compatibility