PerformanceElementTiming.toJSON()

Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.

The toJSON() method of the PerformanceElementTiming interface is a standard serializer. It returns a JSON representation of the object's properties.

Syntax

toJSON()

Parameters

None.

Return value

json

A JSON object that is the serialization of the PerformanceElementTiming object.

Examples

In this example calling entry.toJSON() returns a JSON representation of the PerformanceElementTiming object, with the information about 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.toJSON());
    }
  });
});
observer.observe({ entryTypes: ["element"] });

Note: This example uses the PerformanceObserver interface to create a list of performance measurement events. In our case we observe the PerformanceEntry.entrytype element in order to use the PerformanceElementTiming interface.

Specifications

Specification
Element Timing API
# dom-performanceelementtiming-tojson

Browser compatibility

BCD tables only load in the browser