We've already explored free and open-source alternatives to many Google apps and services in this series, but there's one critical category we haven't mentioned yet: messaging services. Keeping in touch with friends and family is what most people use phones for, but as with social media, the vast majority of messaging platforms are black boxes with questionable data practices.

Switching to a new messaging app also usually means you have to convince some friends or family members to make the jump, which can be a much more difficult transition than switching email or note-taking applications. Still, if you can convince a few people (or if you're just interested in public chat rooms), we've compiled some of the best options below.

Why does open-source matter?

Free and open-source software (FOSS) has a number of advantages, but to most people, the main benefit is privacy. All the code is out in the open, so anyone with programming knowledge can go through it and see exactly what an app is doing. Proprietary apps can sometimes feel like black boxes, where you don't really know what's going on behind the scenes. That's rarely the case with FOSS.

I say 'almost,' because there's technically nothing stopping open-source apps from spying on you, but that behavior is extremely rare. If a developer is doing something they're not supposed to be, like spying on users or bundling malware, they probably wouldn't announce it to the world.

Many people simply prefer open-source apps out of principle, in the same way that some people prefer shopping at locally-owned stores instead of Walmart or Target. These apps are often created by individuals or small groups in their spare time, as opposed to large companies with income generated from advertising or venture capital.

What we didn't include

Before jumping to our top picks for open-source messaging apps, I wanted to point out a few popular methods of communication and why they aren't included on this list, before the comments asking why pour in.

Telegram is often cited as being open-source, and it's arguably the most popular messaging service with that distinction, at over 200 million monthly active users. While the code for Telegram's desktop and mobile apps has been made available, the server-side component is still a closely-guarded secret, so you can't spin up your own Telegram service.

XMPP and IRC have been popular messaging protocols for decades, with plenty of open-source server and client applications to choose from. However, I'm not including any XMPP and IRC clients here, because they aren't optimized for mobile in the same way that Riot.im/Matrix is (one of the services I'll get to later). If you really want to hit up an IRC chatroom from your phone, there are apps for that, but you'll either miss messages or be forced to deal with a constant background process.

Signal

If you're looking for a simple and secure messaging app for phones, you can't go wrong with Signal. It has been around for years, and not only are both the mobile apps and server software open-source, but Signal has also passed several security audits with flying colors.

No accounts or complicated setup processes are necessary: just download the app, put in your phone number, and you're done. You can optionally set it as your phone's SMS application, and when you go to text someone, the message will be sent over Signal if the other person has the app set up (similar to how iMessage works).

Signal is end-to-end encrypted, so no one else can peep your messages, not even Signal itself. Even group chats are encrypted, thanks to some wizardry with security keys. Google used Signal's encryption method for the encrypted chats in its Allo app — anyone remember Allo?

Signal also has most of the other features you would expect from a modern texting app, like video/audio calls, temporary messages, and emoji reactions. However, there is no support for group calls, and each user has to be attached to a phone number.

In short, Signal is simple enough that anyone who has used popular messaging apps won't run into issues, while also having better security and privacy than mainstream options like Facebook Messenger or WhatsApp. It's definitely worth a try.

Signal Private Messenger
Signal Private Messenger

Riot.im

If you're more in the market for something like Slack and Discord, you should try Riot.im. Riot uses the somewhat-new Matrix protocol, which gives you access to a network of independently-operated servers, each with their own collection of rooms. It's sort of like how email works — you can create an account on one server, and then use that account to send and receive messages from any other Matrix server. It's completely de-centralized and open-source.

The Riot.im app guides you through creating an account on the Riot.im Matrix server, but if you'd like, you can log in with any other Matrix provider. Once you do that, you can create a room, join an existing room, or send direct messages to anyone else on the Matrix network. In most cases, messages are end-to-end encrypted.

The interface is a little bit intimidating at first (it took me a while to figure out how to join a room on another server), but the feature set is impressive. There's also a desktop/browser client that looks and feels a lot like Discord, which might be a better place to start than the Android app. The mobile app also seems to occasionally get stuck while loading new rooms, for whatever reason.

Matrix is widely seen as the successor to platforms like IRC, but unlike IRC, messages are stored on the server (so you can read missed messages later). Its open-source and decentralized nature has made it a popular choice in the Linux, free software, and cryptocurrency communities — the room for Manjaro Linux is one of the most popular, with over 13,000 members alone. There are also bridges for interacting with some IRC and Telegram servers.

So, if you want to set up a chat room for you and friends/family members that works great across mobile and desktop platforms alike, you should definitely give Riot.im a spin.