What is the issue with the HTML Standard?

If the video and audio elements offered loading="lazy" support, it would allow authors to defer loading of expensive resources until those elements are near the visible viewport. The attribute could also be used to determine how other desirable features behave, such as when autoplay starts playing, and when a video's poster image is fetched.

(Note: this issue was updated Jan 2026 to include the audio element)

For example, loading=lazy combined with the autoplay attribute could cause a video to delay its poster image loading, its data fetching (other than metadata perhaps?), and its autoplay behavior until the video element is in (near) the viewport. Per my understanding, lazy autoplay is currently doable with JavaScript and it'd be great to offer a declarative HTML alternative.

Could <video loading="lazy" ..></video> be one already-familiar way to offer a set of lazy behaviors for video?

Note Jan 22, 2026: After discussions in #11980 we're broadening the scope of this issue include Audio Element support, as video and audio share common use cases for lazy loading and share a media element implementation underneath.