PerformanceElementTiming: loadTime property

Limited availability

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 loadTime read-only property of the PerformanceElementTiming interface always returns 0 for text. For images it returns the time which is the latest between the time the image resource is loaded and the time it is attached to the element.

Value

A DOMHighResTimeStamp with the loadTime of the element. Always 0 for text.

Examples

Logging loadTime

In this example an <img> element is being observed by adding the elementtiming attribute. A PerformanceObserver is registered to get all performance entries of type "element". The buffered flag is used to access data from before the observer was created. Calling entry.loadTime returns the loadTime of the image element.

html
<img
  src="image.jpg"
  alt="a nice image"
  elementtiming="big-image"
  id="myImage" />

js
const observer = new PerformanceObserver((list) => {
  list.getEntries().forEach((entry) => {
    if (entry.identifier === "big-image") {
      console.log(entry.loadTime);
    }
  });
});
observer.observe({ type: "element", buffered: true });