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

The state read-only property of the TelephonyCall interface returns the current state of the phone call.


var state = myCall.state;


A DOMString.

Call state possible values

State String Description
alerting The phone has successfully connected to the remote party across the network, and the 'alerting' ring tone can now be heard by the caller.
connected The phone has successfully connected to the number being called, and the receiving phone has answered the call.
dialing The phone is currently dialing out to place the call.
disconnected The call has ended.
held The call is currently on hold.
incoming The call is in the process of being received.

Obsolete call state values

The following states were available in older implementations of the API, but not in the latest master code. Transient states are no longer used, and busy is not really a state, so is instead covered by one of the possible return values of TelephonyCall.disconnectedReason.

State String Description
busy The number that was dialed for this call is busy.
connecting The number has been dialed and the phone is attempting to connect.
disconnecting The call is in the process of being disconnected.
holding The call is entering a "hold" state.
resuming The call is returning from hold to an active state.


// Telephony object
var tel = navigator.mozTelephony;

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

  // Get the state of the incoming call; should return 'incoming'

  // Answer the call


Specification Status Comment
Web Telephony Draft Draft.

Browser compatibility

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

Supported in Firefox OS 1.0.1.

See also