Whether you want to share something with a friend or discuss something confidentially with a colleague, there is no shortage of messaging apps. End-to-end encryption serves as the backbone of WhatsApp, Signal and Telegram, three of the most popular messaging apps. Which one should you choose? Let’s take a look.

Popularity

When it comes to popularity, WhatsApp is the king. With over two billion users, it easily outpaces Telegram and Signal. In various parts of Europe, WhatsApp has even overtaken the use of SMS. On the other hand, WhatsApp has yet to make a dent in the U.S. where only one-third of Internet users have it downloaded.

Telegram has more than 200 million users worldwide. Telegram excels with options like unlimited server storage so your encrypted files are saved on the company’s cloud system. Group member capacity is another Telegram upside with a capacity of 5,000 users all at once. Whereas WhatsApp communicates using your phone number, Telegram offers a username feature to ensure continued anonymity.

With a user-base of under one million users, Signal is obviously less popular than WhatsApp or Telegram. For Signal, its popularity has grown as the most secure messaging app around. That’s especially true in the news world where the app allows reporters and journalists to reach sources confidentially. Signal definitely has room to grow, but to do so it will have to steal users from its competitors, and that is a tall order.

Privacy

WhatsApp’s ownership by Facebook leads to questions about its intentions with user data. Messages are sent with end-to-end encryption so that only your device and the recipient’s device can read them. The app backs up your messages, so if you switch devices, all of your data is available.

In 2016, WhatsApp amended its Privacy Policy to allow the sharing of data from WhatsApp to Facebook. It remains unclear exactly what Facebook does with WhatsApp user data. An anonymous Facebook executive in 2018 blew the whistle on Facebook’s focus on selling user data. Facebook may not abuse WhatsApp user data (yet), but the company’s track history offers plenty of reasons for skepticism.

Telegram is also under the microscope, even with a focus on user privacy. All user messages are sent with end-to-end encryption. The company emphasizes it will not use its data to show you ads and only stores what is necessary to keep the app secure. However, In the last few years a number of security concerns have arisen around potential hacker targets. In May 2017, MIT researchers found that hackers could nail down to the second when a Telegram user went online or offline.

In July 2019, Symantec discovered how “media file jacking” could be used to grab user information. Telegram updated its user privacy in March 2019 to remove a 48-hour rule for unsending any message. You can now delete any conversation, including ones that happened years ago, and deny it ever took place. This does not say that Telegram is insecure or that it uses user data improperly. However, as with WhatsApp, Telegram users should never consider anything 100% secure or private.

When it comes to privacy, Signal touts it above all else. As an open-source app, it offers the most transparent approach to privacy. Its underlying code can be verified by anyone with interest. Anyone can look for and attempt to identify holes and then work to have them plugged to prevent malicious use. Its guarding of user privacy is so strong, the European Commission has advised its staff to switch to Signal. It is one of the only messaging apps that doesn’t store metadata or use the cloud to back up messages. Ultimately, Signal has been in the news more for its security features than its privacy lapses.

Compatibility

WhatsApp has the best compatibility of the bunch. Available on Android, iOS, Windows, Mac and the Web, the only place WhatsApp doesn’t work by default is on Linux. However, third-party options do exist on Linux where there is unofficial support. Messages are available across all platforms, so you can start a message on your desktop app and pick it up on your phone. Support is available on more than forty language platforms around the world.

Telegram adds official support for Linux along with apps for Android, iOS, Windows and Mac. It lacks Web-based support, but that is hardly a reason not to use the service. Telegram adds support for well over thirty languages.

Signal also offers Android, iOS, Windows, macOS and Linux support. There is no web-based platform, and plans to support one in the future have not been announced. The app adds support for seven languages.

Features

WhatsApp offers its own strong feature-set including voice and video calling; voice messaging; group chats and video calls; support for documents like PDFs, documents, spreadsheets, slideshows and more. The group chat feature can support up to 256 people simultaneously.

Telegram offers a hugely popular service called “Secret Chats.” These ensure someone cannot take a screenshot of the conversation and a message cannot be forwarded. Additionally, Telegram has a self-destruct timer for you to permanently remove messages. You can choose a time between one second and one week before a message disappears permanently.

Sending large files along with a variety of file types up to 1.5GB in size (pictures, video, documents, audio, zip files, etc.) is another huge plus for Telegram. Comparatively, WhatsApp’s limit for file transfers is only 100MB. Customization is another Telegram-specific feature. You can choose how the app opens links, choose dominant colors and more.

For Signal, other than the standard text and voice/video call features, it adds a fun layer of expression with encrypted stickers that are only seen by the sender and recipient. You can even create your own sticker packs.

Which One Should You Choose?

Most people will likely choose WhatsApp simply because it is the most popular and where you will find your friends and family. However, the fact that it is owned by Facebook could be a concern for those who are worried about their data privacy. If you are using WhatsApp, don’t forget to take these security precautions.

Choosing Telegram is best for someone who wants a more polished interface and the largest group chat size available. With a strong mix of security, privacy and “Secret Chats,” it has a solid combination. That it includes “Channels” for broadcasting to larger audiences makes it a good app for quickly disseminating news and information.

When you decide to use Signal, you are likely doing so because you want to go all in on privacy. Signal is the most secure of the three messaging apps. It’s the app of choice for newsrooms around the world looking for a secure way to connect with anonymous sources. The biggest downside is its comparatively small audience which makes it a tough sell for groups of friends.