IntersectionObserver.observe()

This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

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.
Working Draft Initial definition.

Browser compatibility

Update compatibility data on GitHub
DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidEdge MobileFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
Basic support
Experimental
Chrome Full support 51Edge Full support 15Firefox Full support 55
Full support 55
No support 53 — 55
Disabled
Disabled 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.
IE No support NoOpera ? Safari ? WebView Android Full support 51Chrome Android Full support 51Edge Mobile Full support YesFirefox Android ? Opera Android ? Safari iOS ? Samsung Internet Android Full support 5.0

Legend

Full support  
Full support
No support  
No support
Compatibility unknown  
Compatibility unknown
Experimental. Expect behavior to change in the future.
Experimental. Expect behavior to change in the future.
User must explicitly enable this feature.
User must explicitly enable this feature.

See also

Document Tags and Contributors

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