The onstorage property of the WindowEventHandlers mixin is an EventHandler for processing storage events.

The storage event fires when a storage area has been changed in the context of another document.


 window.onstorage = functionRef;


functionRef is a function name or a function expression. This function receives a StorageEvent as its sole argument.


This example logs the value for a storage key whenever it changes in another document.

window.onstorage = function(e) {
  console.log('The ' + e.key +
    ' key has been changed from ' + e.oldValue +
    ' to ' + e.newValue + '.');


Specification Status Comment
HTML Living Standard
The definition of 'onstorage' in that specification.
Living Standard

Browser compatibility

ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
onstorageChrome Full support 1Edge Full support ≤18Firefox Full support 45IE ? Opera Full support 15Safari ? WebView Android Full support ≤37Chrome Android Full support 18Firefox Android Full support 45Opera Android Full support 14Safari iOS ? Samsung Internet Android Full support 1.0


Full support
Full support
Compatibility unknown
Compatibility unknown

See also