WindowOrWorkerGlobalScope

The WindowOrWorkerGlobalScope mixin describes several features common to the Window and WorkerGlobalScope interfaces. Each of these interfaces can, of course, add more features in addition to the ones listed below.

Note: WindowOrWorkerGlobalScope is a mixin and not an interface; you can't actually create an object of type WindowOrWorkerGlobalScope.

Properties

These properties are defined on the WindowOrWorkerGlobalScope mixin, and implemented by Window and WorkerGlobalScope.

WindowOrWorkerGlobalScope.caches Read only: Returns the CacheStorage object associated with the current context. This object enables functionality such as storing assets for offline use, and generating custom responses to requests.
WindowOrWorkerGlobalScope.crossOriginIsolated Read only: Returns a boolean value that indicates whether a SharedArrayBuffer can be sent via a Window.postMessage() call.
WindowOrWorkerGlobalScope.indexedDB Read only: Provides a mechanism for applications to asynchronously access capabilities of indexed databases; returns an IDBFactory object.
WindowOrWorkerGlobalScope.isSecureContext Read only: Returns a boolean indicating whether the current context is secure (true) or not (false).
WindowOrWorkerGlobalScope.origin Read only: Returns the origin of the global scope, serialized as a string.

Methods

These methods are defined on the WindowOrWorkerGlobalScope mixin, and implemented by Window and WorkerGlobalScope.

WindowOrWorkerGlobalScope.atob(): Decodes a string of data which has been encoded using base-64 encoding.
WindowOrWorkerGlobalScope.btoa(): Creates a base-64 encoded ASCII string from a string of binary data.
WindowOrWorkerGlobalScope.clearInterval(): Cancels the repeated execution set using WindowOrWorkerGlobalScope.setInterval().
WindowOrWorkerGlobalScope.clearTimeout(): Cancels the delayed execution set using WindowOrWorkerGlobalScope.setTimeout().
WindowOrWorkerGlobalScope.createImageBitmap(): Accepts a variety of different image sources, and returns a Promise which resolves to an ImageBitmap. Optionally the source is cropped to the rectangle of pixels originating at (sx, sy) with width sw, and height sh.
WindowOrWorkerGlobalScope.fetch(): Starts the process of fetching a resource from the network.
WindowOrWorkerGlobalScope.queueMicrotask(): Enqueues a microtask—a short function to be executed after execution of the JavaScript code completes and control isn't being returned to a JavaScript caller, but before handling callbacks and other tasks. This lets your code run without interfering with other, possibly higher priority, code, but before the browser runtime regains control, potentially depending upon the work you need to complete.
WindowOrWorkerGlobalScope.setInterval(): Schedules a function to execute every time a given number of milliseconds elapses.
WindowOrWorkerGlobalScope.setTimeout(): Schedules a function to execute in a given amount of time.

Specifications

Specification	Status	Comment
HTML Living Standard The definition of '`WindowOrWorkerGlobalScope` mixin' in that specification.	Living Standard	This is where the main mixin is defined.

Browser compatibility

Update compatibility data on GitHub

	Desktop						Mobile
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
`WindowOrWorkerGlobalScope`	Chrome Full support 4	Edge Full support Yes	Firefox Full support 1	IE Full support Yes	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support 18	Firefox Android Full support 4	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support 1.0
`atob`	Chrome Full support Yes	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 27 Notes Notes `atob()` ignores all space characters in the argument to comply with the latest HTML5 spec (see bug 711180). Full support 57 Notes Notes `atob()` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 10	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 4 Full support 4 Full support 27 Notes Notes `atob()` ignores all space characters in the argument to comply with the latest HTML5 spec (see bug 711180). Full support 57 Notes Notes `atob()` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android ?	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`btoa`	Chrome Full support Yes	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 52 Notes Notes `btoa()` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 10	Opera Full support Yes	Safari Full support Yes	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 4 Full support 4 Full support 52 Notes Notes `atob()` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android ?	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`caches` Experimental	Chrome Full support 40	Edge ?	Firefox Full support 42 Full support 42 Full support 52 Notes Notes `caches` now defined on `WindowOrWorkerGlobalScope` mixin.	IE No support No	Opera ?	Safari No support No	WebView Android Full support Yes	Chrome Android Full support Yes	Firefox Android Full support 42 Full support 42 Full support 52 Notes Notes `caches` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support Yes	Safari iOS Full support Yes	Samsung Internet Android Full support Yes
`clearInterval`	Chrome Full support 4	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 52 Notes Notes `clearInterval()` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 4 Notes Full support 4 Notes Notes From Internet Explorer 4 through 8, `clearInterval` is an Object rather than a Function. This behavior was fixed in Internet Explorer 9.	Opera Full support 4	Safari Full support 4	WebView Android Full support 1	Chrome Android Full support 18	Firefox Android Full support 4 Full support 4 Full support 52 Notes Notes `clearInterval()` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 1.0
`clearTimeout`	Chrome Full support 45	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 52 Notes Notes `clearTimeout()` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 4 Notes Full support 4 Notes Notes From Internet Explorer 4 through 8, `clearTimeout` is an Object rather than a Function. This behavior was fixed in Internet Explorer 9.	Opera Full support 4	Safari Full support 4	WebView Android Full support 45	Chrome Android Full support 45	Firefox Android Full support 4 Full support 4 Full support 52 Notes Notes `clearTimeout()` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 5.0
`createImageBitmap`	Chrome Full support 50	Edge No support No	Firefox Full support 52 Notes Full support 52 Notes Notes `createImageBitmap()` now defined on `WindowOrWorkerGlobalScope` mixin. Full support 42	IE No support No	Opera Full support Yes	Safari No support No	WebView Android Full support 50	Chrome Android Full support 50	Firefox Android Full support Yes	Opera Android Full support Yes	Safari iOS ?	Samsung Internet Android Full support 5.0
`crossOriginIsolated` ExperimentalNon-standard	Chrome No support No	Edge No support No	Firefox Full support 72	IE No support No	Opera No support No	Safari No support No	WebView Android No support No	Chrome Android No support No	Firefox Android No support No	Opera Android No support No	Safari iOS No support No	Samsung Internet Android No support No
`fetch` Experimental	Chrome Full support 42	Edge Full support 14	Firefox Full support 39 Full support 39 Full support 34 Disabled Disabled From version 34: this feature is behind the `dom.fetch.enable` preference. To change preferences in Firefox, visit about:config. Full support 52 Notes Notes `fetch()` now defined on `WindowOrWorkerGlobalScope` mixin.	IE No support No	Opera Full support 29 Full support 29 Full support 28 Disabled Disabled From version 28: this feature is behind the `Experimental Web Platform Features` preference.	Safari Full support 10.1	WebView Android Full support 42	Chrome Android Full support 42	Firefox Android Full support 39 Full support 39 Full support 34 Disabled Disabled From version 34: this feature is behind the `dom.fetch.enable` preference. To change preferences in Firefox, visit about:config. Full support 52 Notes Notes `fetch()` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 29 Full support 29 Full support 28 Disabled Disabled From version 28: this feature is behind the `Experimental Web Platform Features` preference.	Safari iOS Full support 10.3	Samsung Internet Android Full support 4.0
`indexedDB`	Chrome Full support 24	Edge Full support Yes	Firefox Full support 16 Full support 16 Full support 10 Prefixed Prefixed Implemented with the vendor prefix: moz Full support 52 Notes Notes `indexedDB` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Partial support 10	Opera Full support 15	Safari Full support 7	WebView Android Full support Yes	Chrome Android Full support 25	Firefox Android Full support 22 Full support 22 Full support 52 Notes Notes `indexedDB` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 14	Safari iOS Full support 8	Samsung Internet Android Full support 2.0
`isSecureContext` Experimental	Chrome Full support 55	Edge ?	Firefox Full support 52	IE ?	Opera ?	Safari ?	WebView Android Full support 55	Chrome Android Full support 55	Firefox Android Full support 52	Opera Android ?	Safari iOS ?	Samsung Internet Android Full support 6.0
`origin`	Chrome Full support 59	Edge ?	Firefox Full support 54	IE No support No	Opera No support No	Safari No support No	WebView Android Full support 59	Chrome Android Full support 59	Firefox Android Full support 54	Opera Android No support No	Safari iOS No support No	Samsung Internet Android Full support 7.0
`queueMicrotask`	Chrome Full support 71	Edge No support No	Firefox Full support 69	IE No support No	Opera Full support 58	Safari Full support 12.1	WebView Android Full support 71	Chrome Android Full support 71	Firefox Android No support No	Opera Android Full support 50	Safari iOS Full support 12.2	Samsung Internet Android Full support 10.0
`setInterval`	Chrome Full support 30	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 52 Notes Notes `setInterval` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 4	Opera Full support 4	Safari Full support 1	WebView Android Full support Yes	Chrome Android Full support 30	Firefox Android Full support 4 Full support 4 Full support 52 Notes Notes `setInterval` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 3.0
`setTimeout`	Chrome Full support 30	Edge Full support Yes	Firefox Full support 1 Full support 1 Full support 52 Notes Notes `setInterval` now defined on `WindowOrWorkerGlobalScope` mixin.	IE Full support 4	Opera Full support 4	Safari Full support 1	WebView Android Full support Yes	Chrome Android Full support 30	Firefox Android Full support 4 Full support 4 Full support 52 Notes Notes `setInterval` now defined on `WindowOrWorkerGlobalScope` mixin.	Opera Android Full support 10.1	Safari iOS Full support 1	Samsung Internet Android Full support 3.0

Legend

Full support: Full support
Partial support: Partial support
No support: No support
Compatibility unknown: Compatibility unknown
Experimental. Expect behavior to change in the future.: Experimental. Expect behavior to change in the future.
Non-standard. Expect poor cross-browser support.: Non-standard. Expect poor cross-browser support.
See implementation notes.: See implementation notes.
User must explicitly enable this feature.: User must explicitly enable this feature.
Requires a vendor prefix or different name for use.: Requires a vendor prefix or different name for use.