Window: self property
Baseline Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since July 2015.
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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
).
Value
A WindowProxy object.
Examples
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:
const w1 = window;
const w2 = self;
const w3 = window.window;
const w4 = window.self;
// w1, w2, w3, w4 all strictly equal, but only w2 will function in workers
Specifications
Specification |
---|
HTML # dom-self-dev |
Browser compatibility
See also
- Its
Worker
equivalent,WorkerGlobalScope.self
.