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IntersectionObserver.observe()

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.

The IntersectionObserver method observe() adds an element to the set of target elements being watched by the IntersectionObserver. One observer has one set of thresholds and one root, but can watch multiple target elements for visibility changes in keeping with those. To stop observing the element, call IntersectionObserver.unobserve().

When the visibility of the specified element crosses over one of the observer's visibility thresholds (as listed in IntersectionObserver.thresholds, the observer's callback is executed with an IntersectionObserverEntry representing the intersection change which occurred. Note that this design allows multiple elements' intersection changes to be processed by a single call to the callback using an array of IntersectionObserverEntry objects.

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Syntax

IntersectionObserver.observe(targetElement);

Parameters

targetElement
An element whose visibility within the root is to be monitored. This element must be a descendant of the root element (or contained wtihin the current document, if the root is the document's viewport).

Return value

undefined.

Examples

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Specifications

Specification Status Comment
Intersection Observer
The definition of 'IntersectionObserver.observe()' in that specification.
Editor's Draft Initial definition.

Browser compatibility

FeatureChromeFirefoxEdgeInternet ExplorerOperaSafari
Basic Support51

53 — 551

55

15(No)??
FeatureAndroidChrome for AndroidEdge mobileFirefox for AndroidIE mobileOpera AndroidiOS Safari
Basic Support5151(Yes)?(No)??

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.

See also

Document Tags and Contributors

 Contributors to this page: fscholz, UsainBloot, tazsingh, Sheppy
 Last updated by: fscholz,