Instant messaging (IM) technology is a type of online chat that offers real-time text transmission over the Internet. A LAN messenger operates in a similar way over a local area network. Short messages are typically transmitted between two parties, when each user chooses to complete a thought and select “send”. Some IM applications can use push technology to provide real-time text, which transmits messages character by character, as they are composed. More advanced instant messaging can add file transfer, clickable hyperlinks, Voice over IP, or video chat.
Non-IM types of chat include multicast transmission, usually referred to as “chat rooms”, where participants might be anonymous or might be previously known to each other (for example collaborators on a project that is using chat to facilitate communication). Instant messaging systems tend to facilitate connections between specified known users (often using a contact list also known as a “buddy list” or “friend list”). Depending on the IM protocol, the technical architecture can be peer-to-peer (direct point-to-point transmission) or client-server (an Instant message service center retransmits messages from the sender to the communication device).
By 2010, instant messaging over the Web was already in sharp decline, in favor of messaging features on social networks. The most popular IM platforms, such as AIM, closed in 2017, and Windows Live Messenger was merged into Skype. Today, most instant messaging takes place on messaging apps which by 2014 had more users than social networks.
For IM’ing to work as intended, both users must be online at the same time, although nearly all instant messaging platforms now allow asynchronous interactions between online and offline users. If offline messaging is not supported, attempting to IM an unavailable user will result in a notification that the transmission cannot be completed. In addition, the intended recipient must be willing to accept instant messages, as it is possible to configure the IM client to reject certain users.
When an IM is received, it alerts the recipient with a window containing the incoming message. Or, depending on the user’s settings, a window could indicate an IM has arrived along with a prompt to accept or reject it. Many IM clients also notify the user audibly with a distinctive sound, such as a chime or chirp. The user can also be notified visually by flashing the IM window or its taskbar icon when a message has arrived.
While IM clients were frequently based on proprietary protocols in the past — requiring both users to use the same software in order to communicate — the adoption of open standards has become more common. This has enabled the rise of multi-platform instant messengers, such as Pidgin and Trillian.
Another important shift in IM has been how it’s accessed and delivered. Long deployed as a desktop client that had to be downloaded and installed, instant messaging is now more often found as a feature within another web- or cloud-based service — such as Facebook, Gmail and Skype — or as a mobile app, such as WhatsApp Messenger.
Features of instant messaging
The exchange of text has long been the chief function of instant messaging, but it is now one feature of many. The ability to insert images and emojis into messages is now standard in many clients, as are file transfers. Facebook Messenger even enables users to send money via IM. Numerous clients now support the escalation from IM to other modes of communication, such as group chat, voice calls or video conferencing.
Presence enables users to see the availability of their contacts — not only whether they are online or offline, but also whether they have indicated their status is free or busy. Some clients also enable users to set an “away message” providing more detail about their limited or lack of availability. Within an active session between two users, most clients can also indicate to one user in real time when the other user is typing.