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

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

The WindowControlsOverlay interface of the Window Controls Overlay API exposes information about the geometry of the title bar area in desktop Progressive Web Apps, and an event to know whenever it changes. This interface is accessible from Navigator.windowControlsOverlay.

EventTarget WindowControlsOverlay

Instance properties

WindowControlsOverlay.visible Read only Experimental

A Boolean that indicates whether the window controls overlay is visible or not.

Instance methods

WindowControlsOverlay.getTitlebarAreaRect() Experimental

Returns the size and position of the title bar.


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

geometrychange Experimental

Fired when the geometry of the title bar area changes.


if ("windowControlsOverlay" in navigator) {
    (event) => {
      if (event.visible) {
        const rect = event.titlebarAreaRect;
        // Do something with the coordinates of the title bar area.


Window Controls Overlay
# windowcontrolsoverlay-interface

Browser compatibility

BCD tables only load in the browser