IntersectionObserver: thresholds property

Baseline Widely available

This feature is well established and works across many devices and browser versions. It’s been available across browsers since March 2019.

The thresholds read-only property of the IntersectionObserver interface returns the list of intersection thresholds that was specified when the observer was instantiated with IntersectionObserver().

If only one threshold ratio was provided when instantiating the object, this will be an array containing that single value.

See the Intersection Observer page to learn how thresholds work.

Value

An array of intersection thresholds, originally specified using the threshold property when instantiating the observer. If only one observer was specified, without being in an array, this value is a one-entry array containing that threshold. Regardless of the order your original threshold array was in, this one is always sorted in numerically increasing order.

If no threshold option was included when IntersectionObserver() was used to instantiate the observer, the value of thresholds is [0].

Note: Although the options object you can specify in the IntersectionObserver() constructor has a field named threshold, this property is called thresholds. If you accidentally use thresholds as the name of the field in your options, the thresholds array will wind up being [0.0], which is likely not what you expect.

Specifications

Specification
Intersection Observer
# dom-intersectionobserver-thresholds

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
thresholds
Chrome – Full support
Chrome 52 (Release date: 2016-07-20)
footnote Full support
Edge – Full support
Edge 15 (Release date: 2017-04-05)
footnote Full support
Firefox – Full support
Firefox 55 (Release date: 2017-08-08)
footnote Full support
Opera – Full support
Opera 39 (Release date: 2016-08-02)
footnote Full support
Safari – Full support
Safari 12.1 (Release date: 2019-03-25)
footnote Full support
Chrome Android – Full support
Chrome Android 52 (Release date: 2016-07-27)
footnote Full support
Firefox for Android – Full support
Firefox for Android 55 (Release date: 2017-08-08)
footnote Full support
Opera Android – Full support
Opera Android 41 (Release date: 2016-10-25)
footnote Full support
Safari on iOS – Full support
Safari on iOS 12.2 (Release date: 2019-03-25)
footnote Full support
Samsung Internet – Full support
Samsung Internet 6 (Release date: 2017-08-23)
footnote Full support
WebView Android – Full support
WebView Android 52 (Release date: 2016-07-27)
footnote Full support
WebView on iOS – Full support
WebView on iOS 12.2 (Release date: 2019-03-25)
footnote Full support

Legend

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

Full support
Full support