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This is an experimental technology
Because this technology's specification has not stabilized, check the compatibility table for usage in various browsers. Also note that the syntax and behavior of an experimental technology is subject to change in future versions of browsers as the specification changes.

The read-only composed property of the Event interface returns a Boolean which indicates whether or not the event will propagate across the shadow DOM boundary into the standard DOM.

This property was formerly named scoped.


var composed = Event.composed;


Boolean which is true if the event will cross from the shadow DOM into the standard DOM after reaching the shadow root (that is, the first node in the shadow DOM in which the event began to propagate). Of course, propagation only occurs at all if the bubbles property is also true. You can determine the path the event will follow as it makes its way through the shadow root to the DOM root by calling composedPath().

If this value is false, the shadow root will be the last node to be offered the event.


Specification Status Comment
The definition of 'composed' in that specification.
Living Standard  

Browser compatibility

Feature Chrome Edge Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support 53.0 ? 52 (52) ? ? ?
Feature Android Android Webview Firefox Mobile (Gecko) Firefox OS IE Mobile Opera Mobile Safari Mobile Chrome for Android
Basic support No support 53.0 52.0 (52) ? ? ? ? 53.0

Document Tags and Contributors

 Contributors to this page: Sheppy, jpmedley
 Last updated by: Sheppy,