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.
<img
src="image.jpg"
alt="a nice image"
elementtiming="big-image"
id="myImage" />
const observer = new PerformanceObserver((list) => {
list.getEntries().forEach((entry) => {
if (entry.identifier === "big-image") {
console.log(entry.loadTime);
}
});
});
observer.observe({ type: "element", buffered: true });
Specifications
Specification |
---|
Element Timing API # ref-for-dom-performanceelementtiming-loadtime① |
Browser compatibility
BCD tables only load in the browser