Screen: isExtended property

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

Secure context: This feature is available only in secure contexts (HTTPS), in some or all supporting browsers.

The isExtended read-only property of the Screen interface returns true if the user's device has multiple screens, and false if not.

This property is typically accessed via window.screen.isExtended, and can be used to test whether multiple screens are available before attempting to create a multi-window, multi-screen layout using the Window Management API.


A boolean value — true if the device has multiple screens, and false if not.

Note: If a window-management Permissions-Policy is set that blocks use the Window Management API, isExtended will always return false.


if (window.screen.isExtended) {
  // Create multi-screen window layout
} else {
  // Create single-screen window layout


Window Management
# api-screen-isExtended-attribute

Browser compatibility

BCD tables only load in the browser

See also