Note that properties which are objects (e.g., for overriding the prototype of built-in elements) are listed in a separate section below.

Window.caches Read only Secure context

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.

Window.clientInformation Read only

An alias for Window.navigator.

Window.closed Read only

This property indicates whether the current window is closed or not.

Window.cookieStore Read only Secure context

Returns a reference to the CookieStore object for the current document context.

Window.crashReport Read only Secure context

Returns a CrashReportContext object that enables arbitrary data to be recorded for the current top-level browsing context, which is then added to a CrashReport and sent to a reporting endpoint when a browser crash occurs.

Window.credentialless Read only

Returns a boolean that indicates whether the current document was loaded inside a credentialless <iframe>. See IFrame credentialless for more details.

Window.crossOriginIsolated Read only

Returns a boolean value that indicates whether the website is in a cross-origin isolation state.

Window.crypto Read only

Returns the Crypto object associated to the global object.

Window.customElements Read only

Returns a reference to the CustomElementRegistry object, which can be used to register new custom elements and get information about previously registered custom elements.

Window.devicePixelRatio Read only

Returns the ratio between physical pixels and device independent pixels in the current display.

Window.document Read only

Returns a reference to the document that the window contains.

Window.documentPictureInPicture Read only Secure context

Returns a reference to the document Picture-in-Picture window for the current document context.

Window.fence Read only

Returns a Fence object instance for the current document context. Available only to documents embedded inside a <fencedframe>.

Window.frameElement Read only

Returns the element in which the window is embedded, or null if the window is not embedded.

Window.frames Read only

Returns an array of the subframes in the current window.

Window.fullScreen

This property indicates whether the window is displayed in full screen or not.

Window.history Read only

Returns a reference to the history object.

Window.indexedDB Read only

Provides a mechanism for applications to asynchronously access capabilities of indexed databases; returns an IDBFactory object.

Window.innerHeight Read only

Gets the height of the content area of the browser window including, if rendered, the horizontal scrollbar.

Window.innerWidth Read only

Gets the width of the content area of the browser window including, if rendered, the vertical scrollbar.

Window.isSecureContext Read only

Returns a boolean indicating whether the current context is secure (true) or not (false).

Window.launchQueue Read only

When a progressive web app (PWA) is launched with a launch_handler client_mode value of focus-existing, navigate-new, or navigate-existing, the launchQueue provides access to the LaunchQueue class, which allows custom launch navigation handling to be implemented for the PWA.

Window.length Read only

Returns the number of frames in the window. See also window.frames.

Window.localStorage Read only

Returns a reference to the local storage object used to store data that may only be accessed by the origin that created it.

Window.location

Gets/sets the location, or current URL, of the window object.

Window.locationbar Read only

Returns the locationbar object.

Window.menubar Read only

Returns the menubar object.

Window.mozInnerScreenX Read only

Returns the horizontal (X) coordinate of the top-left corner of the window's viewport, in screen coordinates. This value is reported in CSS pixels. See mozScreenPixelsPerCSSPixel in nsIDOMWindowUtils for a conversion factor to adapt to screen pixels if needed.

Window.mozInnerScreenY Read only

Returns the vertical (Y) coordinate of the top-left corner of the window's viewport, in screen coordinates. This value is reported in CSS pixels. See mozScreenPixelsPerCSSPixel for a conversion factor to adapt to screen pixels if needed.

Window.name

Gets/sets the name of the window.

Window.navigation Read only

Returns the current window's associated Navigation object. The entry point for the Navigation API.

Window.navigator Read only

Returns a reference to the navigator object.

Window.opener

Returns a reference to the window that opened this current window.

Window.origin Read only

Returns the global object's origin, serialized as a string.

Window.originAgentCluster Read only

Returns true if this window belongs to an origin-keyed agent cluster.

Window.outerHeight Read only

Gets the height of the outside of the browser window.

Window.outerWidth Read only

Gets the width of the outside of the browser window.

Window.pageXOffset Read only

An alias for window.scrollX.

Window.pageYOffset Read only

An alias for window.scrollY.

Window.parent Read only

Returns a reference to the parent of the current window or subframe.

Window.performance Read only

Returns a Performance object, which includes the timing and navigation attributes, each of which is an object providing performance-related data. See also Using Navigation Timing for additional information and examples.

Window.personalbar Read only

Returns the personalbar object.

Window.scheduler Read only

Returns the Scheduler object associated with the current context. This is the entry point for using the Prioritized Task Scheduling API.

Window.screen Read only

Returns a reference to the screen object associated with the window.

Window.screenX and Window.screenLeft Read only

Both properties return the horizontal distance from the left border of the user's browser viewport to the left side of the screen.

Window.screenY and Window.screenTop Read only

Both properties return the vertical distance from the top border of the user's browser viewport to the top side of the screen.

Window.scrollbars Read only

Returns the scrollbars object.

Window.scrollMaxX Read only

The maximum offset that the window can be scrolled to horizontally, that is the document width minus the viewport width.

Window.scrollMaxY Read only

The maximum offset that the window can be scrolled to vertically (i.e., the document height minus the viewport height).

Window.scrollX Read only

Returns the number of pixels that the document has already been scrolled horizontally.

Window.scrollY Read only

Returns the number of pixels that the document has already been scrolled vertically.

Window.self Read only

Returns an object reference to the window object itself.

Window.sessionStorage

Returns a reference to the session storage object used to store data that may only be accessed by the origin that created it.

Window.sharedStorage Read only Secure context

Returns the WindowSharedStorage object for the current origin. This is the main entry point for writing data to shared storage using the Shared Storage API.

Window.speechSynthesis Read only

Returns a SpeechSynthesis object, which is the entry point into using Web Speech API speech synthesis functionality.

Window.statusbar Read only

Returns the statusbar object.

Window.toolbar Read only

Returns the toolbar object.

Window.top Read only

Returns a reference to the topmost window in the window hierarchy. This property is read only.

Window.trustedTypes Read only

Returns the TrustedTypePolicyFactory object associated with the global object, providing the entry point for using the Trusted Types API.

Window.viewport Read only

Returns a Viewport object instance, which provides information about the current state of the device's viewport.

Window.visualViewport Read only

Returns a VisualViewport object which represents the visual viewport for a given window.

Window.window Read only

Returns a reference to the current window.

window[0], window[1], etc.

Returns a reference to the window object in the frames. See Window.frames for more details.

Named properties

Some elements in the document are also exposed as window properties:

  • For each <embed>, <form>, <iframe>, <img>, and <object> element, its name (if non-empty) is exposed. For example, if the document contains <form name="my_form">, then window["my_form"] (and its equivalent window.my_form) returns a reference to that element.
  • For each HTML element, its id (if non-empty) is exposed.

If a property corresponds to a single element, that element is directly returned. If the property corresponds to multiple elements, then an HTMLCollection is returned containing all of them. If any of the elements is a navigable <iframe> or <object>, then the contentWindow of first such iframe is returned instead.