With Facebook finally changing how WhatsApp works so that they can profit off of the users (as expected), many people are choosing to switch to other internet messaging apps like Signal & Telegram. We’ve already talked about how naïve that is given there isn’t really anything stopping Signal & Telegram from changing their policies or adding anti-features in the future (they have already). If you haven’t had your ear to the ground in places like the Fediverse or Free Open Source Software communities, you probably haven’t heard of Delta Chat.

Yes, it’s yet another internet messaging app, but it does things in a way that is much more “freedom-friendly” for users. It has an interface that’s almost exactly the same as what you’re used to in WhatsApp, Signal, and Telegram. It repurposed the Signal interface from Signal’s open-source client code, so if you’re familiar with that already, it’s going to be very easy to use.

Delta Chat is an open-source program that’s still in development so there are bugs, but it’s still very usable. There are versions of the app for Android, iOS, Linux, macOS, and Windows, so practically every platform is covered. You can download any of the versions here, and you can communicate any bugs and wishes here. Meanwhile, let’s look at how Delta Chat is better than many of the other popular electronic messaging apps.

1. You already have an account

Delta Chat uses the most widely used international network of internet messaging in existence: email. If you have an Android device, or iOS device, or Mac, or Windows PC, or an Xbox, or a Playstation, or a Nintendo Switch, or a job, or a bank account, or went to school at some point during the information age, or ever downloaded an app from an app store, then you probably already have an email account.

2. It works with the largest user base on the internet

Almost 4 billion people(1) have at least one email account already. That’s probably the entire population of the internet. WhatsApp’s 2 billion user base is dwarfed by the number of users with email accounts. Delta Chat works with all of those people out of the box with no need to pressure them into installing a different app and building another network silo. There is no messaging network silo here, and that’s a huge advantage. But if your friends do want to use Delta Chat, they might like it better than their default email apps.

3. It doesn’t require your phone number

One of the worst things about WhatsApp, Signal, and Telegram is that all of them require your phone number to create an account. This can be a violation of your privacy since your phone number can be associated with your real identity, bank accounts, address, place of work, etc. It can also be used to create relationship maps. If you give any of those apps access to your contacts list, it will scrape the phone numbers and match them with phone numbers in the service’s centralized server database in order to tell you which users have accounts on the platform you’re using. That should be recognized as another privacy violation. I can easily tell who has what app by matching their phone numbers without their permission or knowledge. In the case of Facebook, they can probably match your WhatsApp contacts with Facebook contacts and create an even larger relationship map thus making manipulation via advertisements even easier. Also see: Why are we still using phone numbers?

Delta Chat doesn’t need to create relation maps in order to tell you who else you can chat with because you can chat with literally everybody. You just need to know their email address which is probably already in your contacts list. No server side contact matching required.

4. You can use your own servers

What’s more, you already have a server! Delta Chat works with any email server that supports open standard IMAP protocols. It probably won’t work very well with more proprietary security-focused services like ProtonMail and Tutonota. Practically anything else can be set up within Delta Chat. Of course, Gmail and many other free consumer email services work right away via OATH 2.0 authentication, but if you really care about privacy and security, you’ll want to use your own self-hosted email server or at least a more trustworthy one. There are many ways to build your own email server in your home. Many big businesses run their own servers (which will also work with Delta Chat). There are thousands of paid email hosting services as well. Email hosting often comes free with website hosting or internet service. You can even buy a pre-made email server to use privately (See: Helm).

5. It’s less likely to stop working

The ability to use your own servers or any server you want is very important for longevity and stability. Remember when the Signal servers went down in January? That meant no one could use it. This single point of failure should be a clue as to one reason why centralized services are potentially bad. With Delta Chat, if one person’s IMAP/SMTP server goes down, the people who use that server are the only ones affected. Everyone else using the thousands and thousands of other servers on the internet are all still functional. And if your server goes down permanently, you can easily switch to another. If you control your own domain name’s DNS mail exchange records, you can switch servers without changing your account address.

6. You control your data (if you want to)

Another important feature of decentralized servers, especially when you host your own, is the issue of who controls your data. If you own the server, you decide what the policies are. If you use WhatsApp, Mark Zuckerberg decides. If you use Signal, Moxie Marlinspike decides. If you use Telegram, Pavel Durov decides. You’ve already seen what happens when WhatsApp changes things, what’s stopping Signal & Telegram from adding anti-features, too? Nothing? In fact, there has already been a case of Signal changing things for the worse… see the disabling of federation capabilities in 2016. The precedent has been set with Telegram as well. In 2018, Telegram agreed to allow Russian government agencies access to user data in return for lifting their ban on the app. With the ability to make your own server or choose a server/service that you trust, you have much more freedom and potentially better privacy & security.

7. It doesn’t take your conversations hostage

Along the same lines as “You control your data”, the Delta Chat app doesn’t take your conversations hostage either. You can still access all of those messages from any other email client that connects to your server (as long as you don’t delete them). I can reply to messages I get in Delta Chat from Gnome Evolution or FairEmail or Mutt or webmail or any of the hundreds of other email clients out there. That’s a huge advantage over particularly WhatsApp, Facebook Messenger, and Apple iMessage which all require the company-dictated software app. While the Signal client app is open source, Moxie does not allow any forked/modified clients to connect to the Open Whisper network, so you won’t get any flexibility there. Telegram technically allows 3rd party clients as well, but they are very primitive and not nearly as diverse as the ecosystem of email clients available.

One “gotcha” here is the issue of message encryption, however. If you want to read your encrypted messages on other clients, you’ll have to copy your encryption keys over and the other clients will need to have message encryption support installed. Having the option is a huge advantage, but it’s not completely fleshed out or easy on Delta Chat just yet.

8. You can use your own Video Chat server

IMAP and SMTP can’t really do video/voice calls though, so Delta Chat solves this in another really smart decentralized manner. In the settings, there’s a field to add your own Video Chat Instance! That’s right, you’re not stuck with using whatever someone else chooses for you. That’s even more freedom! If you don’t have your own Video Chat server instance, you can use the free open Jitsi Meet hosted instance by typing in https://meet.jit.si/$ROOM. When you send a Video Chat request to a user, it will create a link to a WebRTC room that the other users can click on to join. WebRTC video chat rooms are supported by most modern web browsers these days, so people can join from phones or larger personal computers. On Android and iOS, in the case of Jitsi Meet, you can also join the calls from the also open-source Jitsi Meet apps which work quite nicely. In the future, Delta Chat should be able to recognize the video chat requests and load a more “phone ringing” style notification.

9. It’s more difficult for governments to block

Yet another disadvantage of centralized services like WhatsApp, Signal, and Telegram is how easy they are to block. All you have to do is cut off the connection to that one set of server hostnames or IP addresses. China, for example, has blocked all three of those messaging apps. Signal had a clever workaround for this called domain fronting, but that no longer works either and Signal continues to be blocked in these countries. Telegram is also blocked in many countries and as a previously mentioned example of policy changes and adding anti-features on the fly… Russia lifted their block on Telegram in 2018 when Telegram agreed to let the Russian government read encrypted user messages. So much for security and privacy, right?

IMAP & SMTP email servers, on the other hand, are more difficult to block since there are so many of them and so many of them are actually used by businesses, educational, and government institutions. Email even works in China (except Gmail). Blocking email would mean basically shutting down everything on the internet. In fact, the internet’s global eCommerce ecosystem depends on email. Even if a country blocks all external internet traffic, an email server would still work within that country or within any kind of internal network that you might have. For example, a business can have its own internal network where email messages never even leave the premises when sent between employees. That kind of high security is not really possible with centralized chat apps like WhatsApp, Signal, and Telegram.

Delta Chat has gained some popularity in countries like Belarus and Russia with people fighting against the dictatorships there… and partly because the governments tried to block downloads of the apps in the smartphone app stores. Delta Chat is available through FDroid as well as an APK download and you can even build it from the source code, so the workaround for an app store block is easy.

10. More control over spam

On electronic messaging apps that use your phone number as an identifier, you really don’t have much control over who can contact you. Anyone can put any series of numbers into the app, verify which sets of numbers have messaging accounts on which platforms without the recipient’s permission, and start sending them messages. Since Delta Chat uses email as the backbone, you have way more control over who can contact you and how. First of all, the built-in options let you completely ignore emails that aren’t sent from Delta Chat on the other end. That kind of breaks the open nature of email messaging, so I would say that’s an extreme solution. You can also filter new emails as “contact requests” and choose to create chats with them on an individual basis. That’s just what’s part of the app though.

Going back to the “you can use your own server” feature, that means you can also add any number of other spam filter protections on the server. If you don’t have your own server, you can use all of the capabilities on the server that you already have. You probably have some very robust filtering capabilities already, even on free consumer email services like Gmail, Outlook.com, Yahoo, AOL, etc. If you do use your own server or a different type of host, then your options open up even further. If your current email account is just overrun with spam, another easy fix is to create a new address for actual communications and only give the new address to people you want to communicate with. (Keep a separate spam account for the shopping, newsletter, app subscription garbage.) It’s not so easy to do something like that with a phone number since the new one you’re getting is probably already attached to a ton of spammer databases.

11. Multiple accounts

Bonus! This one doesn’t really apply to Telegram, since you can set up as many as 3 Telegram accounts with different phone numbers on a single app. WhatsApp and Signal do not allow multiple accounts in a single app though. You’ll have to do some crazy workarounds if you want to do that. Delta Chat implements multiple accounts with an account switcher command in the three dots menu. It’s not the same as other email apps that can combine messages from all sorts of email accounts for a “unified inbox”. Each account is basically in its own silo in this implementation. Still, that’s better than not having multiple account support at all.

What else does Delta Chat do?

Autocrypt end-to-end encryption

A lot of people are often skeptical about the security of email and that was certainly a valid concern back in the late 1900s when email was only a couple of decades old and all we cared about was transferring information electronically instead of shipping it through the postal system. Email is like the World Wide Web though… it hasn’t stood still… it keeps evolving openly. There have been many upgrades to the protocol over the years, including server-side folders, instant push delivery, transport encryption, meeting requests, HTML formatting, and the latest open standard is called Autocrypt. This is a method of exchanging security keys for end-to-end encryption that’s much more user-friendly and open than previous encryption methods.

If two users send each other a message using Delta Chat, the client will automatically start sending encrypted messages by default (after the first two messages are exchanged). If one user is not using Delta Chat, the conversation will remain unencrypted in order to ensure compatibility since the person on the other end may not be using a program that supports Autocrypt encryption. However, since Autocrypt is an open standard, it is possible to enable encryption with other email clients, though this is not completely fleshed out just yet. Here’s a list of other email programs that have started implementing Autocrypt encryption and will probably be compatible in the future.

Disappearing Messages

This only works if the other person is also using Delta Chat. You can specify a certain amount of time that the message remains visible before it gets auto-deleted. If the other person is using a different email program, they can copy or forward it still. This limitation gives the recipient more control, but there are ways around disappearing messages on any platform.

Read receipts

A trendy feature in modern instant messaging apps is the little double checkmark icon that shows a sender that the recipient has received and read the message that you sent. Of course, certain email systems (such as Exchange Server) have had this capability for decades. Delta Chat’s implementation does this in a pretty obvious way without any sneaky image links or proprietary methods. It simply sends another email saying that the message has been read. If you’re not using Delta Chat, you’ll see the note as a regular email message. If you are using Delta Chat, you’ll see the little double checkmark icon.

All of the fun things you associate with instant messaging apps have been possible in email since the late 1900s. It’s just that whatever app you were using didn’t have them as part of the user interface. Delta Chat makes sending voice recordings to people easy again (Pocket Outlook on Pocket PC 2000 also had a nice voice message email feature). Emoji and attachments are there too. The group messaging interface is very similar to other chat apps as well. Group messaging in email is, of course, just adding multiple email addresses in the “To” field. Delta Chat makes the “reply all” function default in group messages and thus makes it more difficult to break the group chat accidentally. There is no “reply only to sender” button, in fact. You’d have to specifically start a different conversation with a single person if you wanted to separate from the group messaging thread… and that’s exactly how the other messaging apps work, so this is probably a good thing.

Delta Chat also has a location-sharing feature, but this is still a work in progress as it doesn’t seem to function perfectly just yet. The idea is that you’ll be able to send people your location so that they can find you more easily. I use location sharing in mapping apps all the time when friends are trying to meet up in a specific location (such as Central Park) and there isn’t an easy address to point to. Currently, this feature sends the location of your choosing as a standard KML file attachment. That means non-delta chat users can still open the data, while a Delta Chat user will get a special location-indicator in the chat.

What’s Missing?

Delta Chat currently doesn’t have a “stickers” library for sending to others, but stickers are really just images and animated GIFs, so there’s no reason these couldn’t be added in the future with plug-ins. If you save whatever “stickers” you like to your device’s storage, you’ll still be able to send them.

A “channels” interface is also missing, but channels are just a public version of group messaging. This could easily be implemented with email list servers… something that’s been around for decades. In fact, Delta Chat works fine with existing email list servers already and the Delta Chat development team uses one.

There aren’t any built-in chatbots either, but again this is something that would be very easy to add. Chatbots can easily be programmed to respond via email, so if there’s one you want to use, all you have to do is add its address to a group.

Live typing indicators are not part of Delta Chat yet either. This is kind of a controversial feature anyway and many people don’t want the other end knowing when they’re typing something anyway. It is technically possible to implement this kind of thing with the use of a secondary server.

For the People, by the People

You might remember back in 2017 when I wrote “Hop: How instant messaging should have been done decades ago” which was about an instant messaging app (now called Spike) that didn’t lock you in and force you to peer pressure your friends or colleagues into using the same app. Delta Chat’s concept is similar, but the approach is different. Delta Chat takes a completely open and honest approach to messaging and puts the user in control as much as possible. You can lock it down as much as you want, put everything behind a VPN, make it all work only within your business’s building, or share messages with the entire world. You can also copy the source code and make your own version of the app with different features for free. You have complete control! That kind of freedom is especially important for users in countries where people have been burned by technology dictatorships.

You can download any of the versions here. If you decide to try it out, you can communicate any bugs and wishes here in order to help contribute to the growth of technology freedom.

Originally published Feb 13, 2021:

10 Ways Delta Chat is Better than WhatsApp, Signal, and Telegram (archive.org)