Experimental: This is an experimental technology
Check the Browser compatibility table carefully before using this in production.
The toJSON() method of the NotRestoredReasons interface is a serializer; it returns a JSON representation of the NotRestoredReasons object.
toJSON()None.
A JSON object that is the serialization of the NotRestoredReasons object.
The following function will return a JSON representation of the NotRestoredReasons object of the first PerformanceNavigationTiming object currently present in the performance timeline:
function returnNRR() {
const navEntries = performance.getEntriesByType("navigation");
let navEntry = navEntries[0];
return navEntry.notRestoredReasons.toJSON();
}