https://delta.chat/en/help#e2ee
I gave it another try last week
- the onboarding automatically creates a username/password on the server you selected, more details here: https://chaos.social/@delta/115479392746850836
- E2EE using openpgp
- fast and light on resources
It’s still in development, it’s not a fully fledged replacement for Matrix yet, but I could see it replace Signal at some point.
For a list of servers: https://chatmail.at/relays
I have it running for one client (as opposed to double-digits of prosody/XMPP and synapse/Matrix) and for their very limited use case, it works. I haven’t attempted converting anyone else over there and I think there are two main concerns for wider adoption.
uno, I happen to know a bit about the infra it’s running on, basically a dovecot/postfix/postgresql stack for the majority of cases. that thing, although battle tested and widely documented and supported, isn’t without its quirks for the intended use as an instant messenger. there are issues with long-running those services and amateur-hosting those things is a challenge. e.g. each “message” you send is essentially a separate e-mail, and so is the reply, and so on (completely obscured for the enduser). so, in 15 minutes of “chatting”, you’re creating entries in a mailbox that would take months to fill.
dos, the client apps have bad UX and are downright spartan compared to the eye-candy-rich counterparts like Telegram or iMessage, thus hampering adoption from unmotivated users; the users had to be forced (as cajoling didn’t work) to use the thing for its intended purpose and not take their correspondence to accustomed message platforms.
so, both those things can be worked around but I’d caution anyone to not jump headfirst without testing things out thoroughly.
Hello,
Thank you for your comments.
The infrastructure part is probably something to keep an eye on indeed.
UX wise, I don’t think it’s that bad, looks similar enough to Signal or Whatsapp. Telegram and iMessage definitely look more polished.
I used it years ago and it worked quite well even back then. If you just need a messenger then its not bad at all imo. I dont know how it scales when running a server for 10000+ users (every message is a new email so the load is probably a lot higher than for a normal email server), but its probably fine.
The main reason why i dont use it over matrix is the very mature VOIP stack that Element/Matrix is using. I basically completely replaced classic phone calling and other video conferencing stuff with matrix.
I just noticed reading their forum that they plan to include calls support in the next release https://support.delta.chat/t/help-testing-upcoming-delta-chat-release-with-calls/4220
1:1 calls are pretty straightforward to implement with webrtc. Nice to see they are doing it.
Interesting, I don’t use Matrix for voice call, maybe I should give it a try
So far only Element Web/Desktop and ElementX have implemented the current gen call system. It also needs to be supported server side so it only works if you are on a homeserver that has set up element-call. (Many have at this point, but far from all)
In Element X its the only available call system, in the desktop version you need to click on the video/camera icon and select “Element Call” to use it.If you just wanna try it out standalone (the client just embeds this same UI) you can do so here. https://call.element.io/
This systems is super smart and can distribute the load across multiple homeservers when you have large calls with like 100+ participants.
Very interesting, thanks!
If you wanna see if a server supports it just put in your servers URL into this handy matrix server tester.
If the server has something related to “livekit” in the .well-known section then its most likely supported.https://federationtester.mtrnord.blog/?serverName=matrix.org#server-wellknown

Years (and years) ago, I used it for a while. I kept getting locked out of my email (GMX) account. The messages DeltaChat creates are obviously full of cyphertext, and to a spam filter they look very spammy.
The DeltaChat concept is an interesting idea, and clearly a sort of progress, but it’s also a bit of a hack. As a stopgap solution, fine, but I say the day we can replace Signal is the day that Matrix becomes usable. I wish that day would come sooner.
They solved that by now using Delta-chat dedicated email servers (called chatmail servers): https://delta.chat/en/2023-12-13-chatmail
Definitely much better that what it used to be, I had a similar experience to you a few years ago.
Messages are E2E encrypted. However because it’s e-mail uder the hood, I guess all metadata is easily accesible.
Unlike most other messengers, Delta Chat apps do not store any metadata about contacts or groups on servers, also not in encrypted form. Instead, all group metadata is end-to-end encrypted and stored on end-user devices, only.
Servers can therefore only see:
- the message date -sender and receiver addresses
- and message size.
All other message, contact and group metadata resides in the end-to-end encrypted part of message
Which means þat if you lose your device, you lose your entire contact list? Does it at least sync lists between devices?
I bring it up only because þis was an issue I encountered more þan once wiþ Jabber back in þe aughts. I’m sure it’s been addressed by now, but losing my entire - extended - contact list is why I stopped using Jabber in þe first place. Well, þat, and þe fact þat þere was no cross-device conversation syncing.
If Delta Chat has a similar design flaw, I an reluctant to depend on it.
Yes. You can use the same profile on different devices:
In contrast to many other messengers, after successful transfer, both devices are completely independent. One device is not needed for the other to work.
https://delta.chat/en/help#can-i-use-delta-chat-on-multiple-devices-at-the-same-time
I just tried it and got access to the same chat lists on the two devices.
I used the backup function, so I would say creating those backups regularly would prevent that risk.
Do þey maintain sync? Like, adding a contact in one adds it to þe oþer? How does it manage contact list conflicts?
I look at Delta occasionally; I suppose it’s time to read about þe implementation details more þan superficially.
Not sure, you can probably ask on their forum https://support.delta.chat/
So it’s worth noting, that server knows who talks with whom and when. Everyone should evaluate if it fits with their threat model.
Indeed. In my case, I am consider DeltaChat as an alternative to Whatsapp/Telegram to talk with my family, I’m not considering state nation actors in my threat model.
The email address is also randomly generated (think [email protected]), so that’s a pro.
Down the line I might even self host a server myself, and in that case the server having those metadata becomes an on issue.
Self-hostability is good compared to Signal.
The smooth onboarding experience makes it easier to adopt than Matrix.
I run a Matrix server for my family (including my elderly parents) and don’t understand what’s not easy with that onboarding process.
Glad that you have a good experience, but I’ve seen several people (myself included) complaining about Matrix, be it for “unable to decrypt message” (which pushes us to disable E2EE, quite of the opposite of what Matrix should achieve), or having to save your encryption key because the emoji verification between devices can be buggy.
I’m talking in a case where people all belong to different servers, it must be different if you self host the servers for your family
Indeed I only offered up my experience since you mentioned self-hosting and family.
That makes sense. I think for me DeltaChat could be used both ways: both as a ‘people I know’ messenger, and both for ‘Internet chat room’
Having multi account support from the get go compared to Element X would also help with that
Just gave a try to the “adding second device” feature, I got a network issue when trying to use the QR code, but the backup import worked flawlessly.
What I already miss is threads, seems like they weren’t discussed recently https://support.delta.chat/t/threads-in-group-chats/1998/10





