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


The messageClass property provides the class of a given message. SMS Classes are defined within the GSM-SMS specification and represent how a SMS message must be carried and handled on the device.


var class = instanceOfMozMmsMessage.messageClass;


A string.

It can have five possible values:

  • class-0 : It indicates a Class 0 SMS. Such a message is displayed on the mobile phone immediately and a message delivery report is sent back to the carrier. The message does not have to be saved in the mobile phone or on the SIM card. This type is also referred to as Flash SMS.
  • class-1 : It indicates a Class 1 SMS. Such a message is stored in the memory of the mobile phone or the SIM card.
  • class-2 : It indicates a Class 2 SMS. Such a message carries SIM card data. The SIM card data must be successfully transferred prior to sending acknowledgment to the carrier. An error message is sent to the carrier if this transmission is not possible.
  • class-3 : It indicates a Class 3 SMS. Such a message is forwarded from the receiver to another device. The delivery acknowledgment is sent to the carrier regardless of whether or not the message was forwarded to the other device.
  • normal : It's the same as class-1.


This is a non-standard implementation, but it is discussed at W3C as part of the System Application Working Group.

Specification Status Comment
Messaging API Editor's Draft Editor Draft (WIP).

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) IE Mobile Opera Mobile Safari Mobile
Basic support No support 12.0 (12.0) Moz No support No support No support

See also


© 2016 Mozilla Contributors
Licensed under the Creative Commons Attribution-ShareAlike License v2.5 or later.

API B2G DOM Firefox OS Mobile Property Reference Référence WebSMS