ViewTimeline: startOffset property

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The startOffset read-only property of the ViewTimeline interface returns a CSSNumericValue representing the starting (0% progress) scroll position of the timeline as an offset from the start of the overflowing section of content in the scroller.

Value

A CSSNumericValue.

Examples

See the main ScrollTimeline page for an example.

Specifications

Specification
Scroll-driven Animations
# dom-viewtimeline-startoffset

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
startOffset
Chrome – Full support
Chrome 115 (Release date: 2023-07-18)
footnote Full support
Edge – Full support
Edge 115 (Release date: 2023-07-21)
footnote Full support
Firefox – No support
Firefox
footnote
footnote See bug 1676779
Opera – Full support
Opera 101 (Release date: 2023-07-26)
footnote Full support
Safari – Full support
Safari 26 (Release date: 2025-09-15)
footnote Full support
Chrome Android – Full support
Chrome Android 115 (Release date: 2023-07-21)
footnote Full support
Firefox for Android – No support
Firefox for Android
footnote
footnote See bug 1676779
Opera Android – Full support
Opera Android 77 (Release date: 2023-08-31)
footnote Full support
Safari on iOS – Full support
Safari on iOS 26 (Release date: 2025-09-15)
footnote Full support
Samsung Internet – Full support
Samsung Internet 23 (Release date: 2023-10-18)
footnote Full support
WebView Android – Full support
WebView Android 115 (Release date: 2023-07-21)
footnote Full support
WebView on iOS – Full support
WebView on iOS 26 (Release date: 2025-09-15)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support
No support
No support
See implementation notes.

See also