PerformancePaintTiming: toJSON() method

The toJSON() method of the PerformancePaintTiming interface is a serializer; it returns a JSON representation of the PerformancePaintTiming object.

Syntax

js
toJSON()

Parameters

None.

Return value

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

Examples

undefined

Using the toJSON method

In this example, calling entry.toJSON() returns a JSON representation of the PerformancePaintTiming object.

js
const observer = new PerformanceObserver((list) => {
  list.getEntries().forEach((entry) => {
    console.log(entry.toJSON());
  });
});

observer.observe({ type: "paint", buffered: true });

This would log a JSON object like so:

json
{
  "name": "first-contentful-paint",
  "entryType": "paint",
  "startTime": 234.5,
  "duration": 0
}

To get a JSON string, you can use JSON.stringify(entry) directly; it will call toJSON() automatically.

Specifications

See also