PerformanceEntry: toJSON() method

{{APIRef("Performance API")}}{{AvailableInWorkers}}

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

Syntax

toJSON()

Parameters

None.

Return value

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

Examples

Using the toJSON method

In this example, calling entry.toJSON() returns a JSON representation of the {{domxref("PerformanceMark")}} object.

performance.mark("debug-marker", {
  detail: "debugging-marker-123",
});

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

observer.observe({ entryTypes: ["mark"] });

This would log a JSON object like so:

{
  "name": "debug-marker",
  "entryType": "mark",
  "startTime": 158361,
  "duration": 0
}

Note that it doesn't contain PerformanceMark's {{domxref("PerformanceMark.detail", "detail")}} property.

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")}}