PerformancePaintTiming: toJSON() method
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since April 2021.
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
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
| Specification |
|---|
| Paint Timing # dom-performancepainttiming-tojson |