This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.

A DOMRequest object represents an ongoing operation. It provides callbacks that are called when the operation completes, as well as a reference to the operation's result. A DOM method that initiates an ongoing operation may return a DOMRequest object that you can use to monitor the progress of that operation.

Note: This feature is available in Web Workers.


A callback handler called when the operation represented by the DOMRequest is completed.
A callback handler that gets called when an error occurs while processing the operation.
A string indicating whether or not the operation is finished running. Its value is either "done" or "pending".
The operation's result.
Error information, if any.




An example of using the onsuccessonerror, result, and error properties of a DOMRequest object.

var pending = navigator.mozApps.install(manifestUrl);

pending.onsuccess = function () {
  // Save the App object that is returned
  var appRecord = this.result;
  alert('Installation successful!');
pending.onerror = function () {
  // Display the name of the error
  alert('Install failed, error: ' +;


Not currently part of any specification.

Browser compatibility

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support ? 13.0 (13.0) ? ? ?
Available in workers ? 41.0 (41.0) ? ? ?
Feature Android Chrome for Android Firefox Mobile (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support ? ? 13.0 (13.0) ? ? ?
Available in workers ? ? 41.0 (41.0) ? ? ?

See also

Document Tags and Contributors

 Contributors to this page: fscholz, chrisdavidmills, teoli, jsx, kscarfone, Jeremie, ethertank, Sheppy, markg
 Last updated by: fscholz,