PerformancePaintTiming: toJSON() method

{{APIRef("Performance API")}}

The toJSON() method of the {{domxref("PerformancePaintTiming")}} interface is a {{Glossary("Serialization","serializer")}}; it returns a JSON representation of the {{domxref("PerformancePaintTiming")}} object.

Syntax

toJSON()

Parameters

None.

Return value

A {{jsxref("JSON")}} object that is the serialization of the {{domxref("PerformancePaintTiming")}} object.

Examples

Using the toJSON method

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

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:

{
  "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

{{Specifications}}

Browser compatibility

{{Compat}}

See also

• {{jsxref("JSON")}}