WhatsApp and Signal are two of the most popular messaging and calling apps on smartphones and computers. We tested both to see which one you should use if you had to choose just one.

Signal and WhatsApp offer robust end-to-end encryption for both calls and messages. They also support all major smartphone and computer operating systems. Signal offers better protection for personal and device data, making it a great choice for communicating with security-conscious friends. Still, most of your contacts are probably already on WhatsApp due to its popularity, so that’s the app you’ll realistically use the most.

WhatsApp's increasing focus on professional business tools and built-in social features is likely to further increase its popularity, despite the knowledge that it sends some user and device data to parent company Meta (Facebook).

Signal and WhatsApp both have impressive platform and device support. Both services have official apps for Mac and Windows PCs, Android tablets and smartphones, and iPhones. Support isn’t the same, however, as Signal has an official iPad and Linux app, while WhatsApp does not. WhatsApp does, however, have a really solid web app that can be accessed through most major web browsers on any device, including Linux computers.