Signal

Key features

• End-to-end encryption on everything State-of-the-art end-to-end encryption powered by the open-source Signal Protocol covers every message and every call, with privacy on by default rather than as an optional mode.[1]

• Rich messaging over data Text, voice messages, photos, videos, GIFs, and files travel over the phone data connection, avoiding SMS and MMS fees, with high-fidelity messages and HD voice and video calls.[1][2]

• Voice and video calls Crystal-clear voice and video calls reach contacts across town or across the ocean with no long-distance charges.[1]

• Group chats Group chats keep families, friends, and coworkers connected in one conversation.[1]

• Encrypted stickers Encrypted sticker packs add expression to chats, and users can create and share their own packs.[1]

• No ads or trackers Signal carries no ads, no affiliate marketers, and no tracking, as stated on its homepage.[1]

• Free nonprofit operation Signal is an independent 501c3 nonprofit that cannot be acquired, funded by grants and donations that pay for servers, bandwidth, and development.[1][2]

• Apps on five platforms Native apps cover Android, iPhone and iPad, Windows, Mac, and Linux, with direct APK distribution alongside the Play Store.[1][2]

Who will love it

• People leaving ad-funded chat apps Readers whose current messenger monetizes attention get encrypted messaging with a nonprofit funding model and no advertising or tracking.[1][2]

• Individuals and small private groups Per-phone-number accounts with direct and group chats fit personal communication and small-group coordination rather than managed team deployments.[1][2]

• Auditors who read client code Readers who want to inspect what they run get AGPLv3-licensed clients in Kotlin and Java with public development on GitHub.[1][2]

Who should avoid it

• Phone number is mandatory Registration requires a phone number for verification codes, and the desktop app cannot be used without Signal on a phone, so numberless or desktop-only setups are not possible.[1][2]

• Centralized service with no self-host path Only the centralized hosted service is documented, with no supported self-hosted deployment, so operators who must hold their own messaging infrastructure should look at federated options such as Element.[1][2]

• The deciding trade If you want free, nonprofit, end-to-end encrypted personal messaging, choose Signal; if you need numberless accounts, self-hosting, or stated SSO and support guarantees, choose a vendor that documents them.[1][2]

Fit and portability