This article is in need of a technical review.

This feature is not on a current W3C standards track, but it is supported on the Firefox OS platform. Although implementations may change in the future and it is not supported widely across browsers, it is suitable for use in code dedicated to Firefox OS apps.

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

The number read-only property of the TelephonyCall interface indicates the telephone number associated with the current phone call. Replaced by in Firefox OS 2.0+.


var calledNumber = myCall.number;


A DOMString indicating the number associated with the call. This can be either the number dialed for an outgoing call, or the phone number reported by caller ID for an incoming call.


// Telephony object
var tel = navigator.mozTelephony;

// Place a call
tel.dial("123456789").then(function(call) {

// Receive a call
tel.onincoming = function (e) {
  var incomingCall =;

  // Get the number of the incoming call

  // Answer the call


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 Not supported Not supported Not supported Not supported Not supported
Feature Android Firefox Mobile (Gecko) Firefox OS (Gecko) IE Mobile Opera Mobile Safari Mobile
Basic support Not supported 12.0 (12.0) [1] 1.0.1 [1] Not supported Not supported Not supported

[1] Replaced by in Firefox OS 2.0 (Gecko 32.)

See also

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