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


window.onunload = funcRef;
  • funcRef is a reference to a function.


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 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.


Specification Status Comment
WHATWG HTML Living Standard
The definition of 'GlobalEventHandlers' in that specification.
Living Standard  
The definition of 'GlobalEventHandlers' in that specification.
Working Draft  
The definition of 'GlobalEventHandlers' in that specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)
Feature Android Firefox Mobile (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support (Yes) (Yes) (Yes) (Yes) (Yes)

Document Tags and Contributors

 Last updated by: teoli,