LargestContentfulPaint: toJSON() method
Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The toJSON()
method of the LargestContentfulPaint
interface is a serializer; it returns a JSON representation of the LargestContentfulPaint
object.
Syntax
js
toJSON()
Parameters
None.
Return value
A JSON
object that is the serialization of the LargestContentfulPaint
object.
The JSON doesn't contain the element
property because it is of type Element
, which doesn't provide a toJSON()
operation.
Examples
Using the toJSON method
In this example, calling entry.toJSON()
returns a JSON representation of the LargestContentfulPaint
object.
js
const observer = new PerformanceObserver((list) => {
list.getEntries().forEach((entry) => {
console.log(entry.toJSON());
});
});
observer.observe({ type: "largest-contentful-paint", buffered: true });
This would log a JSON object like so:
json
{
"name": "",
"entryType": "largest-contentful-paint",
"startTime": 468.2,
"duration": 0,
"size": 19824,
"renderTime": 468.2,
"loadTime": 0,
"id": "",
"url": ""
}
To get a JSON string, you can use JSON.stringify(entry)
directly; it will call toJSON()
automatically.
Specifications
Specification |
---|
Largest Contentful Paint # dom-largestcontentfulpaint-tojson |
Browser compatibility
BCD tables only load in the browser