IntersectionObserverEntry.intersectionRect

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

The IntersectionObserverEntry interface's read-only intersectionRect property is a DOMRectReadOnly object which describes the smallest rectangle that contains the entire portion of the target element which is currently visible within the intersection root.

Syntax

var intersectionRect = IntersectionObserverEntry.intersectionRect;

Value

A DOMRectReadOnly which describes the part of the target element that's currently visible within the root's intersection rectangle.

This rectangle is computed by taking the intersection of boundingClientRect with each of the target's ancestors' clip rectangles, with the exception of the intersection root itself.

Example

In this simple example, an intersection callback stores the intersection rectangle for later use by the code that draws the target elements' contents, so that only the visible area is redrawn.

function intersectionCallback(entries) {
  entries.forEach(function(entry) {
    refreshZones.push({
      element: entry.target,
      rect: entry.intersectionRect
    });
  });
}

Specifications

Specification Status Comment
Intersection Observer
The definition of 'IntersectionObserverEntry.intersectionRect' in that specification.
Working Draft Initial definition

Browser compatibility

DesktopMobile
ChromeEdgeFirefoxInternet ExplorerOperaSafariAndroid webviewChrome for AndroidFirefox for AndroidOpera for AndroidSafari on iOSSamsung Internet
intersectionRect
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 Full support YesSafari ? WebView Android Full support 51Chrome Android Full support 51Firefox 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.