Signal is not the most popular, but if you need privacy and security, this app is definitely the way to go. Signal is remarkably easy to use, open source and trusted by security experts.

TL;DR: Activist Handbook recommends activists to use Signal. It is the most privacy-friendly chat app that is easy to use as well.

Want to compare? Check out our reviews of other chat apps.

Popularity #

Although Signal is not widely used, it has gained significant popularity under activists, journalists and politicians recently.

Functionality #

The app is available on iPhone, Android, Mac, Windows and even Linux. Signal also offers voice and video calling, although it is not possible to use it in groups. The app has built in censorship circumvention for countries such as China. It is possible to let your messages disappear automatically after a while. Recently, stickers and link previews have been added as well.

At times, it might take a little while longer before new functionality comes to Signal. However, once it does arrive, one can be assured its privacy and security aspects are very well thought out. Check out their blog for updates.

Security and privacy #

Signal always uses end-to-end encryption. The developers of Signal have gone through great lengths to make Signal as privacy friendly and secure as possible. The app is widely recognised as the best option for privacy by security experts. The service stores almost no metadata, so even if authorities request access to user data, they will not be able to share any sensitive information. The app is open source and well documented for other developers to review.

Price and revenue model #

The app is free to use. Signal is a nonprofit organisation and relies on donations. Concerns have been raised that Signal and many other privacy focussed organisations receive considerable amounts of money from US funded agencies. Despite these concerns, it still appears to be the most secure option available.