LargestContentfulPaint: size property

Baseline 2025
Newly available

Since December 2025, this feature works across the latest devices and browser versions. This feature might not work in older devices or browsers.

The size read-only property of the LargestContentfulPaint interface returns the intrinsic size of the element that is the largest contentful paint.

The size of the element is the width times height of the rectangle that this element creates on the screen.

Value

An integer representing the width times height of the element.

Examples

Logging the size of the largest contentful paint element

This example uses a PerformanceObserver notifying of new largest-contentful-paint performance entries as they are recorded in the browser's performance timeline. The buffered option is used to access entries from before the observer creation.

js
const observer = new PerformanceObserver((list) => {
  const entries = list.getEntries();
  const lastEntry = entries[entries.length - 1]; // Use the latest LCP candidate
  console.log(lastEntry.size);
});
observer.observe({ type: "largest-contentful-paint", buffered: true });

Specifications

Specification
Largest Contentful Paint
# dom-largestcontentfulpaint-size

Browser compatibility

desktop mobile
Chrome
Edge
Firefox
Opera
Safari
Chrome Android
Firefox for Android
Opera Android
Safari on iOS
Samsung Internet
WebView Android
WebView on iOS
size
Chrome – Full support
Chrome 77 (Release date: 2019-09-10)
footnote Full support
Edge – Full support
Edge 79 (Release date: 2020-01-15)
footnote Full support
Firefox – Full support
Firefox 122 (Release date: 2024-01-23)
footnote Full support
Opera – Full support
Opera 64 (Release date: 2019-10-07)
footnote Full support
Safari – Full support
Safari 26.2 (Release date: 2025-12-12)
footnote Full support
Chrome Android – Full support
Chrome Android 77 (Release date: 2019-09-10)
footnote Full support
Firefox for Android – Full support
Firefox for Android 122 (Release date: 2024-01-23)
footnote Full support
Opera Android – Full support
Opera Android 55 (Release date: 2019-12-03)
footnote Full support
Safari on iOS – Full support
Safari on iOS 26.2 (Release date: 2025-12-12)
footnote Full support
Samsung Internet – Full support
Samsung Internet 12 (Release date: 2020-06-19)
footnote Full support
WebView Android – Full support
WebView Android 77 (Release date: 2019-09-10)
footnote Full support
WebView on iOS – Full support
WebView on iOS 26.2 (Release date: 2025-12-12)
footnote Full support

Legend

Tip: you can click/tap on a cell for more information.

Full support
Full support