PerformanceElementTiming.toJSON()

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

Syntax

var json = PerformanceElementTiming.toJSON();

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) => {
  let entries = list.getEntries().forEach(function (entry) {
    if (entry.identifier === "big-image") {
      console.log(entry.toJSON());
    }
  });
});
observer.observe({ entryTypes: ["element"] });

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

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