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.
IntersectionObserver interface's read-only
root property identifies the
Element whose bounds are treated as the bounding box of the viewport for the element which is the observer's target. If the
null, then the bounds of the actual document viewport are used.
var root =IntersectionObserver.root;
Element object whose bounding box is used as the bounds of the viewport for the purposes of determining how much of the target element is visible. The intersection of this bounding rectangle, offset by any margins specified in the options passed to the
IntersectionObserver() constructor, the target element's bounds, minus the bounds of every element or other object which overlaps the target element, is considered to be the visible area of the target element.
null, then the bounds of the document's viewport (that is, the visible area of the document) are used as the root.
The definition of 'IntersectionObserver' in that specification.
|Editor's Draft||Initial definition|
The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request.
53 — 551
|Feature||Android||Chrome for Android||Edge mobile||Firefox for Android||IE mobile||Opera Android||iOS Safari|
1. From version 53 until version 55 (exclusive): this feature is behind the
dom.IntersectionObserver.enabled preference (needs to be set to
true). To change preferences in Firefox, visit about:config.