This API is available on Firefox OS for internal applications only.

The ready read-only property of the Telephony interface provides an asynchronous notification that the object is initialized.

This is useful because when a Telephony object is created it takes some time to sync the information with the underlying hardware layer and fully initialize. If the code tries to read a value such as before Telephony.ready is resolved, the value may not be correct.


myTelephony.ready.then(function() {
  // do something now telephony is initialized


 A Promise that resolves with void when the telephony object is initialised.


// Telephony object
var tel = navigator.mozTelephony;

tel.ready.then(function() {
  // ok, now let's make some calls


Specification Status Comment
Web Telephony Draft Draft

Browser compatibility

For obvious reasons, support is primarily expected on mobile browsers.

Feature Chrome Firefox (Gecko) Internet Explorer Opera Safari
Basic support No support No support No support No support No support
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support No support 37.0 (37.0) 2.2 No support No support No support

See also

Document Tags and Contributors

 Contributors to this page: chrisdavidmills, teoli
 Last updated by: chrisdavidmills,