Beacon API

The navigator.sendBeacon() method asynchronously sends a small amount of data over HTTP to a web server. It is intended to be used for sending analytics data to a web server. For more details see https://developer.mozilla.org/en-US/docs/Web/API/Beacon_API and https://developer.mozilla.org/en-US/docs/Web/API/Navigator/sendBeacon

navigator.sendBeacon is the only method currently defined for the Beacon API.