autobuffer attribute | autobuffer property
The autobuffer property was initially listed in the W3C spec, but has been dropped. No version of Windows Internet Explorer supports it. Use the preload element instead.
The autobuffer method buffers the audio or video element to prepare for playback. The autobuffer attribute indicates that the media element is likely to be used, even though it does not have an autoplay attribute. This attribute is ignored if autoplay is present. Buffering the media can improve responsiveness when the element is finally played.