MMS

MMS, or Multimedia Messaging Service, is a mobile messaging standard that extends SMS to enable the sending of multimedia content such as images, audio, video, and text. Messages are created on an MMS-capable device, encoded as a MIME multipart message, and transmitted through the operator’s network to a Multimedia Messaging Service Center (MMSC). The MMSC stores the message and delivers a retrieval notification to the recipient, who then downloads the content using their device’s MMS client over a data connection. Content presentation can be described using SMIL, which helps define how text and media are arranged on the recipient’s screen.

The standard was developed by 3GPP and 3GPP2 and became widely deployed in the 2000s as mobile data networks matured. MMS is designed to work across different transport networks and device manufacturers, providing interoperability for messaging between users on different carriers. However, the service relies on a data connection, and delivery depends on network availability; messages may be queued if the recipient is offline.

Typical limitations of MMS include size restrictions, which vary by operator but commonly range from a few hundred kilobytes to around one megabyte per message. The experience is also dependent on the recipient’s device capabilities and network support. Security is another concern; MMS does not generally provide end-to-end encryption, and messages can be stored on carrier servers during transmission.

In modern use, MMS faces competition from internet-based messaging apps that offer richer media features, end-to-end security, and real-time communication. Nonetheless, MMS remains supported in many mobile networks for backward compatibility and for users with devices or plans that still rely on traditional MMS delivery.