Completely different use cases.

Matrix is shared interest groups.

Signal is for personal communication.

Matrix is open source and federated, end of the story.

I prefer matrix for two main reasons:

• I can host my own server (and I do)
• It’s not centralized

As a bonus it has briddes for almost anything you can think of, so I use the signal bridge.

Only because nobody answered with this one:

IRC

Decentralized and an open protocol. Client setup to connect is not so straightforward, but it’s a one and done. Very robust.

I’m allergic to centralized communication schemes, though I do use signal to communicate with one person.

I want to research some of the other suggestions that have been brought up, so thank you for the post!

Simplex

• If you have a targeted group/peer need then whatever they are using or whatever you all decide right in the beginning - I’d suggest Matrix or some other decentralised alternative, definitely not Signal.
  • Matrix had the huge opportunity to be “the messaging app” but they neither became good at corporate usage and definitely ended up sucking at personal usage. They started doing too many things, at once, and while completely ignoring the individual user.
• If you want a wider general acceptance then sadly Matrix is DoA. WhatsApp becomes a huge choice outside USA and China but it has started becoming shittier by the day and looking at who has become WhatsApp’s global head now, I don’t think it’s gonna get any better (check his last “app” or company’s screenshots and come here if you don’t end up vomiting). So Signal or maybe some other similar app. You are limited by societal trends and acceptance here, not the tech or finesse or privacy of an app.
• If you just want privacy and a simpler app, proven (at least so far), then well Signal it is, as much as I hate it for reasons they decided to make it a centralised messaging app and then stuffed crypto in it etc.

I created this to help find active matrix rooms https://activematrixrooms.com/

I use both signal and matrix.

I don’t use either, bcz I use simplex in my personal life. It is really quite great!

Currently me and my friend are using a self-hosted server with Matrix, and Sable as a client.

Sable is the only one with Discord-like functions out of all the clients I’ve tried, all the others falling very short.

Besides that there is Fluxer, which is far more feature complete than any Matrix client. It has some key features holding it back, though, which are no Federation yet, and no E2E encryption yet. But otherwise setting up your own fully functional server is incredibly easily.

Matrix is nice but it’s clear they’re appeasing more towards shareholders than the community, self-hosting via Docker Compose was a PIA as there are 4-5 services that need to talk to one another.

Matrix is only really enjoyable with unencrypted chats.

I have fairly recently switched phones. Now, a good number of older messenges fail to decrypt. Even when I don’t switch devices, a group chat for a three day long event with a very small group already gave us lots of fun decryption errors. Oh, and I have this other fun group chat where Fluffy Chat constantly reminds me that people whose devices I haven’t verified will be able to read my messenges every time I send something. Also, Matrix has coutless clients with different feature sets and I heard calls are a pain to ßet up.

Signal, on the other hand, just works. Federation and decentralization is obviously nice but a functional product is more importmant. I haven’t had a chance to try XMPP unfortunately.

I prefer SecureBit Chat . No account, P2P, EE2E, Quantum resistent.

Do you want it to be so complicated that no one you know in real life is able to use it for more than two weeks before they make some kind of mistake or change that deletes their entire message history and identity? Matrix

Do you want a slim chance that friends and family might use it, but you have to listen to privacy nutjobs tell you your app is a CIA NSA PsyOp and you might as well cc: potus(at)whitehouse(dot)gov all your messages, it’s run by an american non-profit obviously it can’t be trusted? Signal

This is how I explained Matrix to my mom: its like an email address, but for chat. You can chat at me, even if we aren’t using the same server, like someone can send an email from Gmail to Hotmail. She got set up and promptly went back to texting me every dang time.

XMPP is the standard messaging protocol. I recommend Conversations for android, but of course any worthwhile protocol has multiple independent frontends.