The read-only visibilityState property of the XRSession interface is a string indicating whether the WebXR content is currently visible to the user, and if it is, whether it's the primary focus.

Every time the visibility state changes, a visibilitychange event is fired on the XRSession object.

A string indicating whether or not the XR content is visible to the user and if it is, whether or not it's currently the primary focus.

The possible values of visibilityState are:

hidden

The virtual scene generated by the XRSession is not currently visible to the user, so its requestAnimationFrame() callbacks are not being executed until the visibilityState changes. Input controllers are not being handled for the session.

visible

The virtual scene rendered by the XRSession is currently visible to the user and is the primary focus of the user's attention. To that end, the session's requestAnimationFrame() callbacks are being processed at the XR device's native refresh rate and input controllers are being processed as normal.

visible-blurred

While the virtual scene rendered by the XRSession may currently be visible to the user, it is not the user's primary focus at the moment; it's also possible the session is not currently visible at all. In order to optimize resource utilization, the user agent may be handling the session's requestAnimationFrame() callbacks at a throttled rate. Input controllers are not being processed for the session.

It's important to keep in mind that because an immersive WebXR session is potentially being shown using a different display than the HTML document in which it's running (such as when being shown on a headset), the value of a session's visibilityState may not necessarily be the same as the owning document's visibilityState. For instance, if the viewer is using a headset tethered to a computer and the immersive scene is obscured by a configuration UI, the user could peek out from behind the headset and still be able to see the document itself on their computer's monitor.

• visibilitychange event