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LayoutShiftAttribution

The LayoutShiftAttribution interface of the Layout Instability API provides debugging information about elements which have shifted.

Instances of LayoutShiftAttribution are returned in an array by calling LayoutShift.sources.

Properties

LayoutShiftAttribution.Node Read only

Returns the element that has shifted (null if it has been removed).

LayoutShiftAttribution.previousRect Read only

Returns a DOMRectReadOnly object representing the position of the element before the shift.

LayoutShiftAttribution.currentRect Read only

Returns a DOMRectReadOnly object representing the position of the element after the shift.

Methods

LayoutShiftAttribution.toJSON()

Returns a JSON representation of the LayoutShiftAttribution object.

Examples

The following example finds the element that is causing the largest layout shift, and prints that node to the console. For more detail on this see Debug Web Vitals in the field.

function getCLSDebugTarget(entries) {
  const largestEntry = entries.reduce((a, b) => {
    return a && a.value > b.value ? a : b;
  });
  if (largestEntry && largestEntry.sources && largestEntry.sources.length) {
    const largestSource = largestEntry.sources.reduce((a, b) => {
      return a.node && a.previousRect.width * a.previousRect.height >
          b.previousRect.width * b.previousRect.height ? a : b;
    });
    if (largestSource) {
      return largestSource.node;
    }
  }
}

Specifications

Browser compatibility

Desktop Mobile
Chrome Edge Firefox Internet Explorer Opera Safari WebView Android Chrome Android Firefox for Android Opera Android Safari on IOS Samsung Internet
LayoutShiftAttribution
77
80
No
No
64
No
77
77
No
55
No
12.0
currentRect
77
80
No
No
64
No
77
77
No
55
No
12.0
node
77
80
No
No
64
No
77
77
No
55
No
12.0
previousRect
77
80
No
No
64
No
77
77
No
55
No
12.0
toJSON
77
80
No
No
64
No
77
77
No
55
No
12.0

See also

© 2005–2021 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/LayoutShiftAttribution