Choosing an open messenger client: Alternatives to WhatsApp

Keep in touch with far-flung family, friends, and colleagues without sacrificing your privacy.
224 readers like this.
Team communication, chat

Like many families, mine is inconveniently spread around, and I have many colleagues in North and South America. So, over the years, I've relied more and more on WhatsApp to stay in touch with people. The claimed end-to-end encryption appeals to me, as I prefer to maintain some shreds of privacy, and moreover to avoid forcing those with whom I communicate to use an insecure mechanism. But all this WhatsApp/Facebook/Instagram "convergence" has led our family to decide to vote with our feet. We no longer use WhatsApp for anything except communicating with others who refuse to use anything else, and we're working on them.

So what do we use instead? Before I spill the beans, I'd like to explain what other options we looked at and how we chose.

Options we considered and how we evaluated them

There is an absolutely crazy number of messaging apps out there, and we spent a good deal of time thinking about what we needed for a replacement. We started by reading Dan Arel's article on five social media alternatives to protect privacy.

Then we came up with our list of core needs:

  • Our entire family uses Android phones.
  • One of us has a Windows desktop; the rest use Linux.
  • Our main interest is something we can use to chat, both individually and as a group, on our phones, but it would be nice to have a desktop client available.
  • It would also be nice to have voice and video calling as well.
  • Our privacy is important. Ideally, the code should be open source to facilitate security reviews. If the operation is not pure peer-to-peer, then the organization operating the server components should not operate a business based on the commercialization of our personal information.

At that point, we narrowed the long list down to Viber, Line, Signal, Threema, Wire, and While I lean strongly to open source, we wanted to include some closed source and paid solutions to make sure we weren't missing something important. Here's how those six alternatives measured up.


Line is a popular messaging application, and it's part of a larger Line "ecosystem"—online gaming, Taxi (an Uber-like service in Japan), Wow (a food delivery service), Today (a news hub), shopping, and others. For us, Line checks a few too many boxes with all those add-on features. Also, I could not determine its current security quality, and it's not open source. The business model seems to be to build a community and figure out how to make money through that community. (formerly operates on top of the Matrix protocol and therefore lets the user choose a Matrix provider. It also appears to check all of our "needs" boxes, although in operation it looks more like Slack, with a room-oriented and interoperable/federated design. It offers desktop clients, and it's open source. Since the Matrix protocol can be hosted anywhere, any business model would be particular to the Matrix provider.


Signal offers a similar user experience to WhatsApp. It checks all of our "needs" boxes, with solid security validated by external audit. It is open source, and it is developed and operated by a not-for-profit foundation, in principle similar to the Mozilla Foundation. Interestingly, Signal's communications protocol appears to be used by other messaging apps, including WhatsApp.


Threema is extremely privacy-focused. It checks some of our "needs" boxes, with decent external audit results of its security. It doesn't offer a desktop client, and it isn't fully open source though some of its core components are. Threema's business model appears to be to offer paid secure communications.


Viber is a very popular messaging application. It checks most of our "needs" boxes; however, it doesn't seem to have solid proof of its security—it seems to use a proprietary encryption mechanism, and as far as I could determine, its current security mechanisms are not externally audited. It's not open source. The owner, Rakuten, seems to be planning for a paid subscription as a business model.


Wire was started and is built by some ex-Skype people. It appears to check all of our "needs" boxes, although I am not completely comfortable with its security profile since it stores client data that apparently is not encrypted on its servers. It offers desktop clients and is open source. The developer and operator, Wire Swiss, appears to have a pay-for-service track as its future business model.

The final verdict

In the end, we picked Signal. We liked its open-by-design approach, its serious and ongoing privacy and security stance and having a Signal app on our GNOME (and Windows) desktops. It performs very well on our Android handsets and our desktops. Moreover, it wasn't a big surprise to our small user community; it feels much more like WhatsApp than, for example,, which we also tried extensively. Having said that, if we were trying to replace Slack, we'd probably move to

Have a favorite messenger? Tell us about it in the comments below.

Chris Hermansen portrait Temuco Chile
Seldom without a computer of some sort since graduating from the University of British Columbia in 1978, I have been a full-time Linux user since 2005, a full-time Solaris and SunOS user from 1986 through 2005, and UNIX System V user before that.


How many of these are using open source software on server? Maybe only (matrix)?

I miss Telegram on that list.

If you're looking for a multi-platform, feature-oriented security-tight open source messaging app, that's the one that first comes to mind.

Glaring omission, not having Telegram on the list.

In reply to by Lax (not verified)

I think with telegram, everything is more secure.
Check that out.

In reply to by Lax (not verified)

Thanks for the comment, Lax (and Beau, and Peyman). For me, Telegram didn't make the short list due to what I read on Wikipedia:

particularly this:

Telegram's security model has received notable criticism by cryptography experts. They criticized the general security model of permanently storing all contacts, messages and media together with their decryption keys on its servers by default and by not enabling end-to-end encryption for messages by default

which is backed up by references.

Your mileage may vary!

In reply to by Lax (not verified)

I can recommend Delta Chat

Delta Chat is like Telegram or Whatsapp but without the tracking or central control. Check out their GDPR compliancy statement.

Delta Chat doesn’t have their own servers but uses the most massive and diverse open messaging system ever: the existing e-mail server network.

One can chat with anyone if one knows their e-mail address, no need for them to install DeltaChat! All one needs is a standard e-mail account.

Thanks for the comment, Jim Dong.

I had a look at Delta Chat and it is definitely interesting as a chat client; that use of email protocol is pretty cool. However in my case I also wanted audio and video conversations, which WhatsApp and Signal support.

In reply to by jim dong (not verified)

Headline: "Choosing an open messenger client"
Quote, Line: "I could not determine its current security quality, and it's not open source."
I personally have a soft spot for - using email as a transport protocol.

Thanks for the comment, Morten.

Do you know more about Line's security quality and open / closed source status? As far as I was able to determine, it's freeware, not open source, which would immediately disqualify it from "choosing an open messenger client" (the topic of this article).

In the Wikipedia article on Line

I found this comment (backed up with a reference) which made me wonder about things:

Line suppresses content to conform with government censorship.

[update] as to, it looks to be chat-only, correct?

In reply to by Morten Juhl-Jo…

Thanks for the comment, Jon Dazu.

As I mentioned above, I took a quick look at Delta Chat; sure enough it looks interesting, but it doesn't support voice and video conversation, as far as I can tell.

In reply to by Jon Dazu (not verified)

Wasn't there a web chat client in Firefox that goes direct (no servers in-between)? I think it may be called Firefox Hello. And Firefox is cross-platform.

Or if somebody's into hosting, I think there is a plugin for Nextcloud.

Sounds like everybody is willing, and able, to switch to whatever service you decide on. My problem is finding something that satisfies everybody and then convincing them to switch to it!

Thanks for the comment, Drew.

According to this… hello "went away" in FF 49 in September 2016.

I see this related to Nextcloud Talk which looks pretty good. My Nextcloud-fu is pretty rudimentary; are their public instances of Nextcloud out there that would support this kind of use, or must one run their own server?

Your last comment is spot on; probably - for us, anyway - the strongest reason for Signal is that it is pretty much a drop-in replacement for WhatsApp, which our family was already happily using, so convincing everyone to change wasn't hard. Convincing all my colleagues to switch... hmmmm that's another matter.

In reply to by dragonbite

Stunned to see that Jami (formerly GNU Ring) is not on this list! Not only do you get with encrypted/secure messaging but also the ability to transfer files, video and speech at high quality, screen share, all on multiple platforms.

Moreover does not require you to pass any phone number details when setting up.

Though a little more GUI love would be nice, I've had excellent results with home/family tests and I'm about to test it further to see if its suitable for comms between my business partners given its cross platform and should avoid the WhatsApp/hangout headaches.

Hi there, thanks for the article.
I am still searching for good alternatives and am using threema and whatsapp mostly because people I am in contact with use it.
While looking I stumbled upon wich is open source, federated messenger. I am not sure about end-to-end encription and I haven't tried it yet. Have you looked into it, or are there people with experience using it?
thanks in advance

Thanks for the comment, Claus. I haven't looked into Jami but see the previous message.

In reply to by Claus (not verified)

I voted "other" as I use Pidgin. You should take Line off your list. Their aggressive tactics to open-source, third party client developers is disgraceful. They took the worst page out of WhatsApp's textbook and ban the phone numbers of users who use third party clients. That and their agressive DMCA take down policies should deter anyone in the open source community from considering them.
I'd also reconsider against Signal since they have an anti-third-party policy. Not in the spirit of openness if you ask me.

Thanks for your comments, Eion Robb. Any chance you could provide a link supporting your comments?

As far as I can tell, with respect to Signal, you are referring to the matters discussed in this post

which in any case is an interesting read. Thanks for making me go and find it!

In reply to by Eion Robb (not verified)

Thanks for helping me to learn more about messaging. I am anxious to learn more.

I am finding WhatsApp more and more a requirement in my work. I'm going to consider Signal and attempt to get at least a few of my current groups on board. Excellent info.

just started using Signal app on Android. After reading this article, and also recommended to my friends.

I use discord, , free and open source , but some ffmpeg codecs are nonfree.

Creative Commons LicenseThis work is licensed under a Creative Commons Attribution-Share Alike 4.0 International License.