ViewTimeline: subject property

Baseline 2026
Newly available

Since October 2026, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

Want more browser support for this feature? Tell us why.

The subject read-only property of the ViewTimeline interface returns a reference to the subject element whose visibility within its nearest ancestor scrollable element (scroller) is driving the progress of the timeline.