The Beacon interface is used to schedule an asynchronous and non-blocking
request to a web server. Beacon requests use the HTTP PUT method and requests
typically do not require a response. Requests are guaranteed to be initiated
before a page is unloaded and they are run to completion without requiring a
blocking request (for example XMLHttpRequest).
The Beacon interface is used to schedule an asynchronous and non-blocking request to a web server. Beacon requests use the HTTP PUT method and requests typically do not require a response. Requests are guaranteed to be initiated before a page is unloaded and they are run to completion without requiring a blocking request (for example XMLHttpRequest).
MDN
MDN Beacon API
Beacon W3C Working Draft