The following is a comparison of instant messaging protocols. It contains basic general information about the protocols.

Table of instant messaging protocols

ProtocolCreatorFirst public release dateLicenseIdentity (not inc. alias)Asynchronous message relayingTransport Layer SecurityEnd-to-end encryptionUnlimited number of contactsBulletins to all contactsOne-to-many routingSpam protectionGroup, channel or conference supportAudio/VoIP supportWebcam/VideoBatch file sharingMedia synchronizationServerlessProtocol
3GPP standardsFriedhelm Hillebrand1985ProprietaryPhone number (e.g. +15550123)YesNoNoAbout 250 contacts in SIM, unlimited from phone.Noserial messagesMediumNoYes3G-324M/ViLTERCSNo?3GPP standards
BitmessageJonathan Warren2012 NovOpen standardAlphanumeric addressYesYesYesYesNoYesYes (through proof-of-work)YesNoNoYesNoYesBitmessage
BonjourApple Inc.2002 AugustProprietary Freeware; portions under the Apache licenseUsernameNoNoNoYesNomulticastMediumNoNoNoYesNoYesBonjour
BriarBriarproject.org2018 May 9Open standardPublic & Private key (via QR Codes)YesYesYesYesYesYesYesYesNoNoNoNoYesBriar
DiscordDiscord Inc.2015 May 13ProprietaryDiscord IDYesNoNoNoNo?Medium?YesYesYes?NoDiscord
dm3corpus.io / dm3.network2022Open Source (BSD)ENS (Ethereum Name Service)YesYesYesYesYesYesYesYesNoNoNoYesYesdm3
Echospot-on.sf.net / goldbug.sf.net2013Open standardKeyYesOptionalYesYesYesYesYesYesNoNoYesYesYesEcho
Gadu-GaduGG Network2000 Jul 17ProprietaryUIN e.g. 12345678YesYesNoYesNoCentralisticYes (simple)YesYesYesYesNoNoGadu-Gadu
IRCJarkko Oikarinen1988 AugOpen standardNickname!Username@hostname (or "hostmask") e.g. user!~usr@a.b.comYes, via IRCv3 or MemoServ that differs from the main systemOptionalMany implementations which are mostly non-interoperable with other IRC clientsNoNoSimplistic multicastMediumYes (everyone, multiple simultaneous, any size)many implementations which are incompatible with other IRC clientsNoYesvia BNCyes, via DCC CHATIRC
Jami (based on DHT and SIP)Savoir-faire Linux Inc.2002 AugustOpen Standard40-digit addressYesYesYesYesNoYesMediumYesYesYesYesNoYesJami (based on DHT and SIP)
MatrixMatrix.org2014 Sep[failed verification]Open standard@Username:Hostname (MXID)YesYes, mandatoryYes, default for private conversationsYesYesYesYes (using pluggable server-side filtering modules and contact ignoring)YesYesYesYesYesNo (not yet but there is ongoing work on a p2p version:Matrix
MattermostMattermost Inc2015 October 2Open standardMattermost
MSNP (Windows Live Messenger, etc.)Microsoft1999 JulProprietaryEmail address (Microsoft account)YesNoNoOnly for certified robotsNoCentralisticYesYesYesYesYesYesNoMSNP (Windows Live Messenger, etc.)
MTProto (Telegram)Telegram Messenger LLP2013 AugOpen standardPhone number (e.g. +15550123), nickname (e.g. @example)YesYesNo end-to-end encryption for group chatsYesNoYesYes, contact blockingYesYesYesYesYesNoMTProto (Telegram)
MumbleThorvald Natvig1999 JulOpen standardUsernameYesYesNoOnly for certified robotsNoCentralisticYesYesYesNoYesNoNoMumble
LINELY Corporation2011 June 23ProprietaryLINE ID, Phone NumberLINE
OSCAR (AIM, ICQ)AOL1997Proprietary (Discontinued 15-Dec-2017)Username, Email Address or UIN e.g. 12345678YesYes (Aim Pro, Aim Lite)NoNoNoCentralisticclient-basedYes (Multiple, simultaneous)YesYesYesNoNoOSCAR (AIM, ICQ)
StoatStoat2021AGPLv3Username and discriminator (e.g. MysticPixie#7495)YesYesNoYesYesYesYesNoStoat
RVP (Windows Messenger, etc.)Microsoft1997 MarProprietary (Discontinued)Windows Active Directory LoginNoNo?NoCentralisticNoneNo??NoNoNoRVP (Windows Messenger, etc.)
RicochetInvisible.im2014 MarOpen standardTor onion addressYesYesYesYesNoYesYesYesNoNoYesNoYesRicochet
Serval ProjectServal Project2016Open StandardDigit addressYesNoYesYesYesYesNoNoYesYesYesYesYesServal Project
Signal ProtocolSignal Foundation2014 FebOpen standardPhone number (e.g. +15550123), username with two added random trailing numbers (e.g. @example.12)YesYesYesYes?YesYes, client-side contact blocking; server-side protectionsYesYesYesYesYesNoSignal Protocol
SIP/SIMPLEIETF1996Open standarduser@hostnameYesYesOptionalYesYesNoMedium?YesYesYesNoDepends on implementationSIP/SIMPLE
SkypeSkype2003 AugProprietary (Discontinued)UsernameYesProprietaryNoNoNoCentralisticclient-basedYesYesYesYesNoNoSkype
Steam FriendsValve2003 Sep 12ProprietarySteamID/Username or Unique NumberYesProprietary?No, although risingYes?NoYesYesNoNoNoNoSteam Friends
TeamSpeakTeamSpeak Systems GmbH2001 AugProprietaryUnique ID in base64NoNoNo????YesYesNoTeamSpeak
TOC2AOL2005 SepProprietary (Discontinued)Username or UIN e.g. 12345678YesNoNoNoNoCentralisticNopaying members only??Partial?NoTOC2
ThreemaThreema GmbH2012 DecemberOpen standardThreema
TOX (based on DHT)irungentoo (GitHub user)2013 JuneGNU General Public License (GPL) version 3 or laterPublic & Private keyYesYesYesYesYesYesYesYesYesYesYesYesYesTOX (based on DHT)
TuentiTuenti2006ProprietaryUsernameYesYesNoYes?YesYesYesYesYesYes?NoTuenti
WeChatTencent2011ProprietaryUsernameYesYesNoYesYesYesNoYesYesYesNoNoNoWeChat
Windows Messenger serviceMicrosoft1990Proprietary (Discontinued)NetBIOSYesNoNoYesYesYesNoNoNoNoNoNoNoWindows Messenger service
XMPPJeremie Miller, standardized via IETF1999 JanOpen standardJabber ID (JID) e.g. usr@a.b.c/homeYesYesOptionalYesYesYesYesYesYes, via JingleYes, via JingleYesYesOptionalXMPP
YMSG (Yahoo! Messenger)Yahoo!1998, March 9ProprietaryUsernameYesNo[needs update?]NoNoYesCentralisticYesYesYesYesYesNoNoYMSG (Yahoo! Messenger)
Zephyr Notification ServiceMIT1987Open standardKerberos principal e.g. user@ATHENA.MIT.EDUYesNoNoYesYesYesNoYesNoNoNoNoNoZephyr Notification Service
ProtocolCreatorFirst public release dateLicenseIdentity (not inc. alias)Asynchronous message relayingTransport Layer SecurityEnd-to-end encryptionUnlimited number of contactsBulletins to all contactsOne-to-many routingSpam protectionGroup, channel or conference supportAudio/VoIP supportWebcam/VideoBatch file sharingMedia synchronizationServerless (decentralized)Protocol

See also