End-to-end encryption (E2EE) means messages are encrypted on your device and decrypted only on the recipient's; the service in the middle relays ciphertext it cannot read. This is a mathematical property, not a policy promise, done right, the provider couldn't hand over message contents even under compulsion, because it never has them.
What E2EE does not cover: metadata (who, when, how often, see Communication Metadata), the endpoints themselves (malware on a phone reads messages exactly like the owner does), and whatever the person you're talking to screenshots or forwards.
How the common messengers compare
| Messenger | E2EE | Metadata retained | Notes |
|---|---|---|---|
| Signal | Always, everything | Essentially none: account creation date and last-connection date, per its published subpoena responses[1] | Open source, nonprofit, the protocol everyone else borrows; requires a phone number to register, usernames hide it from contacts |
| Always (Signal protocol) | Substantial: contact graph, groups, timing, device info, per its own privacy policy | Content is genuinely protected; the social graph belongs to Meta | |
| Telegram | Only in one-to-one "Secret Chats", regular chats and all groups are readable by the server | Extensive | Widely mistaken for an encrypted messenger; treat cloud chats as semi-public |
| iMessage | Yes, between Apple devices | Moderate | iCloud Backup without Advanced Data Protection stores message keys with Apple, quietly undoing E2EE for backed-up chats |
| SimpleX Chat | Always | Minimal by design; no user identifiers at the protocol level | Smaller ecosystem, rougher edges, strongest metadata story |
| SMS | None | Carrier keeps everything | Legacy fallback, not a messenger |
The pattern worth internalizing: "has encryption" is not the question. The questions are is it on by default for everything, who holds the keys for backups, and what metadata does the operator accumulate.
Settings that matter after you choose
- Disappearing messages by default. The chat log on your phone is the plaintext an attacker or a border agent actually gets. History that doesn't exist can't be extracted. A week or a month is livable.
- Check backup behavior. On iMessage, enable Advanced Data Protection or exclude messages from iCloud Backup; on WhatsApp, turn on encrypted backups explicitly. Your E2EE is only as good as both ends' backups.
- Screen lock and registration lock. A messenger is only as private as the unlocked phone it's on; a registration PIN stops number-hijacking from becoming account takeover.
- Verify safety numbers for the handful of contacts where an impersonation or key-swap would genuinely matter.
Getting people to switch
The hard part of messaging privacy is social, not technical. What works is reducing friction, not lecturing: move one group chat, not a whole social circle; pick the moment a platform has annoyed everyone; be the person who answers fast on the new app. A messenger with slightly weaker properties that your actual contacts use beats a perfect one where nobody is.
If your threat model is serious (source protection, targeted surveillance) the calculus inverts: use the strongest tool (Signal, or SimpleX where phone numbers are themselves a risk) and accept the social cost. Convenience arguments are for threat models that can afford them.
Signal, Government requests and responses, which publishes the subpoenas it receives and the near-empty responses it is able to produce. ↩︎