WorkerGlobalScope: 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.

Note: This feature is only available in Web Workers.

The self read-only property of the WorkerGlobalScope interface returns a reference to the WorkerGlobalScope itself. Most of the time it is a specific scope like DedicatedWorkerGlobalScope, SharedWorkerGlobalScope, or ServiceWorkerGlobalScope.

Value

A global scope object (differs depending on the type of worker you are dealing with, as indicated above).

Examples

If you called

js
console.log(self);

inside a worker, you will get a worker global scope of the same type as that worker object written to the console — something like the following:

DedicatedWorkerGlobalScope {
undefined: undefined, Infinity: Infinity, Math: MathConstructor, NaN: NaN, Intl: Object…}
    Infinity: Infinity
    Array: function Array() { [native code] }
      arguments: null
      caller: null
      isArray: function isArray() { [native code] }
      length: 1
      name: "Array"
      observe: function observe() { [native code] }
      prototype: Array[0]
      unobserve: function unobserve() { [native code] }
      __proto__: function Empty() {}
      <function scope>
    ArrayBuffer: function ArrayBuffer() { [native code] }
    Blob: function Blob() { [native code] }
    Boolean: function Boolean() { [native code] }
    DataView: function DataView() { [native code] }
    Date: function Date() { [native code] }
    DedicatedWorkerGlobalScope: function DedicatedWorkerGlobalScope() { [native code] }
    Error: function Error() { [native code] }
// etc. etc.

This provides a full list of the objects available to that worker scope, so it is quite a useful test if you want to see whether something is available to your worker or not. We also maintain a list of Functions and classes available to Web Workers.

Specifications

Specification
HTML
# dom-workerglobalscope-self-dev

Browser compatibility

desktop mobile server
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
Deno
self
Chrome – Full support
Chrome 4 (Release date: 2010-01-25)
footnote Full support
Edge – Full support
Edge 12 (Release date: 2015-07-29)
footnote Full support
Firefox – Full support
Firefox 3.5 (Release date: 2009-06-30)
footnote Full support
Opera – Full support
Opera 11.5 (Release date: 2011-06-28)
footnote Full support
Safari – Full support
Safari 4 (Release date: 2009-06-08)
footnote Full support
Chrome Android – Full support
Chrome Android 18 (Release date: 2012-06-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 34 (Release date: 2014-12-01)
footnote Full support
Opera Android – Full support
Opera Android 14 (Release date: 2013-05-21)
footnote Full support
Safari on iOS – Full support
Safari on iOS 5 (Release date: 2011-10-12)
footnote Full support
Samsung Internet – Full support
Samsung Internet 1 (Release date: 2013-04-27)
footnote Full support
WebView Android – Full support
WebView Android 4.4 (Release date: 2013-12-09)
footnote Full support
WebView on iOS – Full support
WebView on iOS 5 (Release date: 2011-10-12)
footnote Full support
Deno – Full support
Deno 1 (Release date: 2020-05-13)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support

See also

WorkerGlobalScope