This feature is not Baseline because it does not work in some of the most widely-used browsers.
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The toJSON() method of the LayoutShiftAttribution interface is a serializer that returns a JSON representation of the LayoutShiftAttribution object.
toJSON()
None.
A JSON object that is the serialization of the LayoutShiftAttribution object.
The following example prints a JSON representation of the first item in LayoutShift.sources to the console.
new PerformanceObserver((list) => {
for (const { sources } of list.getEntries()) {
if (sources) {
console.log(sources[0].toJSON());
}
}
}).observe({ type: "layout-shift", buffered: true });
| Specification |
|---|
| Layout Instability API> # sec-layout-shift-attribution> |
| Desktop | Mobile | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Chrome | Edge | Firefox | Opera | Safari | Chrome Android | Firefox for Android | Opera Android | Safari on IOS | Samsung Internet | WebView Android | WebView on iOS | |
toJSON |
84 | 84 | No | 70 | No | 84 | No | 60 | No | 14.0 | 84 | No |
© 2005–2025 MDN contributors.
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.
https://developer.mozilla.org/en-US/docs/Web/API/LayoutShiftAttribution/toJSON