XMPP vs Matrix
Since both protocols position themselves as federated, both protocols are compared mainly in terms of federalism and freedom. In this review, only The Matrix is considered, and not its forks like Gridify and other. Forks of the Matrix protocol can have significant differences. Currently, the Matrix has a clear advantage in supporting client software for all OS, while for financial reasons XMPP dominates only on Android.
|Total active users||~ 2 000 000 000 , including non federated XMPP messengers - WhatsApp, Zoom and etc   In Federated network no known number of active users, but probably more than the number of servers.||Unknown. Matrix.org site is not an authoritative and independent source. Matrix statistics 10 000 000 account include inactive users + users from other messers connected via bridges (!? API of other messengers is designed to connect bots and can be disabled at anytime)|
|Total active servers||~ 80 000||Uknown. Matrix.org site is not an authoritative and independent source. It is generally known that the statistics are overestimated in the group chats of the matrix. 15,000 matrix users create fewer posts than 100 XMPP users
|Open, extensible protocol?||Yes. It is allowed to add the protocols of other messengers to the protocol XMPP (including the Matrix protocol). Anyone can write their own extension and add it to the protocol. An example of a comic expansion: "XEP-0183: Jingle Telepathy Transport" and fork protocol Signal "XEP-0384: OMEMO Encryption". Nobody obliges to use or not to use extensions, but if the extension is in demand it will quickly spread to actively developed XMPP clients. Registration by phone numbers has not gained widespread acceptance, although it has some popularity among lazy users ||No. The protocol cannot be extended without the approval of the owners. If tomorrow the Matrix team makes it mandatory to register by phone and set the spy program, everyone will be obliged to comply.Any unapproved change protocol implies the creation of another new incompatible fork messenger (Matrix 1, Matrix Reload, Matrix Revolutions and etc). Similar splits into hundreds of forks occurred in bitcoin after its popularity, which forces users to install a separate duplicate application for the new fork.
|Commercial project?||No||Symbiosis Company New Vector Ltd (Element/ Riot) (provides paid services) London, United Kingdom + The Matrix.org Foundation C.I.C. (collects donations).|
|Government sponsorship? Developer independence||The French government blocks messengers with e2e encryption in the Apple Store and requires them to go through the state registration procedure. From federal XMPP messengers were blocked Monal (ОМЕМО) and chatSecure (ОМЕМО) )||The French government sponsors Matrix development (Tchap’s) |
|E2E encryption?||OMEMO, OTR, OTR4, PGP ECC, PGP RSA (* It should be noted that OMEMO is a messenger Signal protocol integrated into XMPP as XEP)||OLM|
|Format||XML (Extended HTML version), xml+zlib, JSON ||JSON (base/servers) + HTML/JS (used frequently in clients side), don't support XML
|Monopoly network?||Many servers  and many clients .||Most users use only Matrix.org + Element /Riot (or forks) . Many of the private server owners also use "'element (riot)" domain hosting.|
|Fault-tolerant?||Yes (2 000 000 device to 1 node) (> 1500 users = 1 GB ram )
Cheap small VPS can accommodate the population of entire big cities
|No (< 100 users = 8 GB Ram )
Super computers are required to host large public servers.
|Cost of service 1 active device||> $0.01 / mo||~ $1 / mo|
|Support for one cross-platform client? User-friendliness?||No. Lack of funding. Clients exist on all platforms, but video calls only work well on Android. The commercial XMPP messengers Zoom and WhatsApp do not participate in the federation and do not open the source code||The web client Element (Riot) is based on Electron (Chromium) and has support for all operating systems that support Chromium. There are no commercial matrix-based big messengers (except Element aka Riot)|
|Good sponsorship and advertising support?||No. Most large XMPP servers with billions ( ) of users are not federated and do not invest in the development of the XMPP protocol||Yes. Centralization around one messenger and client allows you to collect investments
|Usage in big network?||XMPP is in usage by Google, WhatsApp, Zoom, IBM, LiveJournal, Nintendo, NSA, US military,Federal Police Germany  and etc... A federated network adapted for millions of private servers with any number of users.
||There are no known cases of using the matrix in any large messengers|
|Can I keep the server on donations?||Donations can pay for the maintenance of big amateur servers. The largest amateur federated server (xmpp.jp) with 886 487 accounts and ~ 30,000 active. .||No. In the matrix, the main load of the network is located on super-nodes that a person with a small budget cannot create. The cost of maintaining amateur supernodes does not pay off the donation. Big supernodes must have commercial sponsors or government support to serve users. The largest amateurs servers host several hundreds active users.  The matrix has not found application in free big messengers, but there are examples of using the matrix in sofrware that require payment for use (remote access program Teamvier).|
|Free Cloudflare TLS proxy. Easy TLS encryption configuration||No, Manual "Let's Encrypt" configuration||You don't need to worry yourself about your safety. Cloudflare proxy can automatically take care of proxying and caching your internet connections traffic, generating and renewing a security certificate. Even a beginner who is not familiar with base TLS encryption can configure and maintain the server. For big servers Matrix.org [] and Element.io [] the cost of its use is individual and depends on the load|
Welcome back to the future! The Matrix's significant commercial successes are based on monopolization network against which the Matrix allegedly ideologically opposes (Signal, WhatsApp, Telegram, Zoom), but offering a really weak federal system. The better federated and decentralized XMPP has funding problems and lags behind in development client software for a couple of years from other monopolistic messengers(Matrix, Signal, WhatsApp [XMPP based], Telegram, Zoom [XMPP based]). From the point of view of XMPP developers, the Matrix is often viewed not as a federal system, but as another kind of monopoly messenger use weak extensibility federation as an advertising strategy.
XMPP funding problems are directly related decentralization and to the reluctance of sponsors and goverements to invest in insubordinate systems