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The Window.self read-only property returns the window itself, as a WindowProxy. It can be used with dot notation on a window object (that is, window.self) or standalone (self). The advantage of the standalone notation is that a similar notation exists for non-window contexts, such as in Web Workers. By using self, you can refer to the global scope in a way that will work not only in a window context (self will resolve to window.self) but also in a worker context (self will then resolve to WorkerGlobalScope.self).


var w = window.self;  // w === window


Uses of window.self like the following could just as well be replaced by window.

if (window.parent.frames[0] != window.self) {
    // this window is not the first frame in the list

Furthermore, when executing in the active document of a browsing context, window is a reference to the current global object and thus all of the following are equivalent:

var w1 = window;
var w2 = self;
var w3 = window.window;
var w4 = window.self;
// w1, w2, w3, w4 all strictly equal, but only w2 will function in workers


Specification Status Comment
WHATWG HTML Living Standard
The definition of 'Window.self' in that specification.
Living Standard No difference from the latest snapshot HTML 5.1
HTML 5.1
The definition of 'Window.self' in that specification.
Recommendation No difference from the HTML5
The definition of 'Window.self' in that specification.
Recommendation First snapshot containing the definition of Window.self.

Browser compatibility

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

See also

Document Tags and Contributors

 Last updated by: erikadoyle,