sendBeacon

Summary

Asynchronously queues small amounts of HTTP data for transfer from the user agent to a web server. For example, it can be used to send analytics or diagnostics code without delaying the page's unload or affecting the performance of the navigation.

Method of dom/Navigatordom/Navigator

Syntax

var result = navigator.sendBeacon(url, data);

Parameters

url

Data-type

any

DOMString

data

Data-type

any

Must be of one of the following types:

• ArrayBufferView
• Blob
• DOMString
• FormData

Return Value

Returns an object of type BooleanBoolean

Boolean

Boolean. Returns one of the following possible values:

Examples

This example queues data for the server on the pagehide event.

function() {
  window.addEventListener('pagehide', logData, false);
  function logData() {
    navigator.sendBeacon(
      'https://putsreq.herokuapp.com/Dt7t2QzUkG18aDTMMcop',
       'Sent by a beacon!');
   }
}();

Related specifications

Beacon

W3C Working Draft

Attributions

• Portions of this content come from HTML5Rocks! article