The onstorage property of the WindowEventHandlers mixin is an event handler 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

BCD tables only load in the browser

See also