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.

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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

See also

WorkerGlobalScope