Window

The Window interface represents a window containing a DOM document; the document property points to the DOM document loaded in that window.

A window for a given document can be obtained using the document.defaultView property.

A global variable, window, representing the window in which the script is running, is exposed to JavaScript code.

The Window interface is home to a variety of functions, namespaces, objects, and constructors which are not necessarily directly associated with the concept of a user interface window. However, the Window interface is a suitable place to include these items that need to be globally available. Many of these are documented in the JavaScript Reference and the DOM Reference.

In a tabbed browser, each tab is represented by its own Window object; the global window seen by JavaScript code running within a given tab always represents the tab in which the code is running. That said, even in a tabbed browser, some properties and methods still apply to the overall window that contains the tab, such as resizeTo() and innerHeight. Generally, anything that can't reasonably pertain to a tab pertains to the window instead.

Instance properties

This interface inherits properties from the EventTarget interface.

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: 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.console Read only: Returns a reference to the console object which provides access to the browser's debugging console.
Window.credentialless Read only Experimental Non-standard: Returns a boolean that indicates whether the current document was loaded inside a credentialless <iframe>. See IFrame credentialless for more details.
Window.crypto Read only: Returns the browser crypto 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.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 Non-standard: 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 Experimental: 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.location: Gets/sets the location, or current URL, of the window object.
Window.locationbar Read only: Returns the locationbar object.
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.menubar Read only: Returns the menubar object.
Window.mozInnerScreenX Read only Non-standard: 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 Non-standard: 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 Experimental: 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.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 Non-standard Read only: The maximum offset that the window can be scrolled to horizontally, that is the document width minus the viewport width.
Window.scrollMaxY Non-standard 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.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.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.

Deprecated properties

Window.defaultStatus Deprecated: Gets/sets the status bar text for the given window.
Window.event Deprecated Read only: Returns the current event, which is the event currently being handled by the JavaScript code's context, or undefined if no event is currently being handled. The Event object passed directly to event handlers should be used instead whenever possible.
Window.external Deprecated Read only: Returns an object with functions for adding external search providers to the browser.
Window.orientation Deprecated Read only: Returns the orientation in degrees (in 90 degree increments) of the viewport relative to the device's natural orientation.
Window.returnValue Deprecated: The return value to be returned to the function that called window.showModalDialog() to display the window as a modal dialog.
Window.sidebar Deprecated Non-standard Read only: Returns a reference to the window object of the sidebar
Window.status Deprecated: Gets/sets the text in the statusbar at the bottom of the browser.

Instance methods

This interface inherits methods from the EventTarget interface.

Window.addEventListener(): Register an event handler to a specific event type on the window.
Window.atob(): Decodes a string of data which has been encoded using base-64 encoding.
Window.alert(): Displays an alert dialog.
Window.blur(): Sets focus away from the window.
Window.btoa(): Creates a base-64 encoded ASCII string from a string of binary data.
Window.cancelAnimationFrame(): Enables you to cancel a callback previously scheduled with Window.requestAnimationFrame.
Window.cancelIdleCallback(): Enables you to cancel a callback previously scheduled with Window.requestIdleCallback.
Window.clearImmediate(): Cancels the repeated execution set using setImmediate().
Window.clearInterval(): Cancels the repeated execution set using setInterval().
Window.clearTimeout(): Cancels the delayed execution set using setTimeout().
Window.close(): Closes the current window.
Window.confirm(): Displays a dialog with a message that the user needs to respond to.
Window.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.
Window.dispatchEvent(): Used to trigger an event.
Window.dump() Non-standard: Writes a message to the console.
Window.fetch(): Starts the process of fetching a resource from the network.
Window.find() Non-standard: Searches for a given string in a window.
Window.focus(): Sets focus on the current window.
Window.getComputedStyle(): Gets computed style for the specified element. Computed style indicates the computed values of all CSS properties of the element.
Window.getDefaultComputedStyle() Non-standard: Gets default computed style for the specified element, ignoring author stylesheets.
Window.getSelection(): Returns the selection object representing the selected item(s).
Window.matchMedia(): Returns a MediaQueryList object representing the specified media query string.
Window.moveBy(): Moves the current window by a specified amount.
Window.moveTo(): Moves the window to the specified coordinates.
Window.open(): Opens a new window.
Window.postMessage(): Provides a secure means for one window to send a string of data to another window, which need not be within the same domain as the first.
Window.print(): Opens the Print Dialog to print the current document.
Window.prompt(): Returns the text entered by the user in a prompt dialog.
Window.queryLocalFonts() Experimental: Returns a Promise that fulfills with an array of FontData objects representing the font faces available locally.
Window.removeEventListener(): Removes an event listener from the window.
Window.reportError(): Reports an error in a script, emulating an unhandled exception.
Window.requestAnimationFrame(): Tells the browser that an animation is in progress, requesting that the browser schedule a repaint of the window for the next animation frame.
Window.requestIdleCallback(): Enables the scheduling of tasks during a browser's idle periods.
Window.resizeBy(): Resizes the current window by a certain amount.
Window.resizeTo(): Dynamically resizes window.
Window.scroll(): Scrolls the window to a particular place in the document.
Window.scrollBy(): Scrolls the document in the window by the given amount.
Window.scrollByLines() Non-standard: Scrolls the document by the given number of lines.
Window.scrollByPages() Non-standard: Scrolls the current document by the specified number of pages.
Window.scrollTo(): Scrolls to a particular set of coordinates in the document.
Window.setImmediate(): Executes a function after the browser has finished other heavy tasks.
Window.setInterval(): Schedules a function to execute every time a given number of milliseconds elapses.
Window.setResizable() Non-standard: Toggles a user's ability to resize a window.
Window.setTimeout(): Schedules a function to execute in a given amount of time.
Window.sizeToContent() Non-standard: Sizes the window according to its content.
Window.showOpenFilePicker() Experimental: Shows a file picker that allows a user to select a file or multiple files.
Window.showSaveFilePicker() Experimental: Shows a file picker that allows a user to save a file.
Window.showDirectoryPicker() Experimental: Displays a directory picker which allows the user to select a directory.
Window.stop(): This method stops window loading.
Window.updateCommands() Non-standard: Updates the state of commands of the current chrome window (UI).

Deprecated methods

Window.back() Non-standard Deprecated: Moves back one in the window history. This method is deprecated; you should instead use history.back().
Window.captureEvents() Deprecated: Registers the window to capture all events of the specified type.
Window.forward() Non-standard Deprecated: Moves the window one document forward in the history. This method is deprecated; you should instead use history.forward().
Window.releaseEvents() Deprecated: Releases the window from trapping events of a specific type.
Window.showModalDialog() Non-standard Deprecated: Displays a modal dialog.

Events

Listen to these events using addEventListener() or by assigning an event listener to the oneventname property of this interface.

error: Fired when a resource failed to load, or can't be used. For example, if a script has an execution error or an image can't be found or is invalid.
languagechange: Fired at the global scope object when the user's preferred language changes.
devicemotion: Fired at a regular interval, indicating the amount of physical force of acceleration the device is receiving and the rate of rotation, if available.
deviceorientation: Fired when fresh data is available from the magnetometer orientation sensor about the current orientation of the device as compared to the Earth coordinate frame.
resize: Fired when the window has been resized.
storage: Fired when a storage area (localStorage or sessionStorage) has been modified in the context of another document.

Animation events

animationcancel: Fired when an animation unexpectedly aborts.
animationend: Fired when an animation has completed normally.
animationiteration: Fired when an animation iteration has completed.
animationstart: Fired when an animation starts.

Clipboard events

copy: Fired when the user initiates a copy action through the browser's user interface. Also available via the oncopy property.
cut: Fired when the user initiates a cut action through the browser's user interface. Also available via the oncut property.
paste: Fired when the user initiates a paste action through the browser's user interface. Also available via the onpaste property.

Connection events

offline: Fired when the browser has lost access to the network and the value of navigator.onLine has switched to false.
online: Fired when the browser has gained access to the network and the value of navigator.onLine has switched to true.

Focus events

blur: Fired when an element has lost focus.
focus: Fired when an element has gained focus.

Gamepad events

gamepadconnected: Fired when the browser detects that a gamepad has been connected or the first time a button/axis of the gamepad is used.
gamepaddisconnected: Fired when the browser detects that a gamepad has been disconnected.

History events

hashchange: Fired when the fragment identifier of the URL has changed (the part of the URL beginning with and following the # symbol).
pagehide: Sent when the browser hides the current document while in the process of switching to displaying in its place a different document from the session's history. This happens, for example, when the user clicks the Back button or when they click the Forward button to move ahead in session history.
pageshow: Sent when the browser makes the document visible due to navigation tasks, including not only when the page is first loaded, but also situations such as the user navigating back to the page after having navigated to another within the same tab.
popstate: Fired when the active history entry changes.

Load & unload events

beforeunload: Fired when the window, the document and its resources are about to be unloaded.
DOMContentLoaded: Fired when the document has been completely loaded and parsed, without waiting for stylesheets, images, and subframes to finish loading.
load: Fired when the whole page has loaded, including all dependent resources such as stylesheets images.
unload: Fired when the document or a child resource is being unloaded.

Manifest events

appinstalled: Fired when the browser has successfully installed a page as an application.
beforeinstallprompt: Fired when a user is about to be prompted to install a web application.

Messaging events

message: Fired when the window receives a message, for example from a call to Window.postMessage() from another browsing context.
messageerror: Fired when a Window object receives a message that can't be deserialized.

Print events

afterprint: Fired after the associated document has started printing or the print preview has been closed.
beforeprint: Fired when the associated document is about to be printed or previewed for printing.

Promise rejection events

rejectionhandled: Sent every time a JavaScript Promise is rejected, regardless of whether or not there is a handler in place to catch the rejection.
unhandledrejection: Sent when a JavaScript Promise is rejected but there is no handler in place to catch the rejection.

Transition events

transitioncancel: Fired when a CSS transition is canceled.
transitionend: Fired when a CSS transition has completed.
transitionrun: Fired when a CSS transition is first created.
transitionstart: Fired when a CSS transition has actually started.

Deprecated events

orientationchange Deprecated: Fired when the orientation of the device has changed.
vrdisplayactivate Deprecated Non-standard: Fired when a display is able to be presented to.
vrdisplayconnect Deprecated Non-standard: Fired when a compatible VR device has been connected to the computer.
vrdisplaydisconnect Deprecated Non-standard: Fired when a compatible VR device has been disconnected from the computer.
vrdisplaydeactivate Deprecated Non-standard: Fired when a display can no longer be presented to.
vrdisplaypresentchange Deprecated Non-standard: Fired when the presenting state of a VR device changes — i.e. goes from presenting to not presenting, or vice versa.

Interfaces

See DOM Reference.

Specifications

Specification
HTML Standard # the-window-object

Browser compatibility

BCD tables only load in the browser