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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 TrackDefaultList interface represents a simple container list for multiple TrackDefault objects.

The TrackDefaultList associated with a particular SourceBuffer can be retrieved using the SourceBuffer.trackDefaults property.


Constructs and returns a new TrackDefaultList object.


Inherits properties from its parent interface, EventTarget.

TrackDefaultList.length Read only
Returns the number of TrackDefault objects in the list.


Inherits properties from its parent interface, EventTarget.

This getter allows the TrackDefault objects in the list to be accessed with an array operator (i.e. [].)




Specification Status Comment
Media Source Extensions
The definition of 'TrackDefaultList' in that specification.
Candidate Recommendation Initial definition.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari (WebKit)
Basic support ? No support ? ? ?
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Phone Opera Mobile Safari Mobile
Basic support ?

No support

No support ? ? No support

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills
 Last updated by: chrisdavidmills,