Tools · Chapter 5
Messaging Apps
Signal, WhatsApp, Telegram, iMessage and SMS across seven privacy properties.
| Feature | Signal | Telegram | iMessage | SMS | |
|---|---|---|---|---|---|
| End-to-end encryption | Always, all features | Messages + calls | Only 'Secret Chats' | Between Apple devices | Never |
| Open source | Fully | No | Partially | No | N/A |
| Metadata collection | Minimal | Extensive (Meta) | Moderate | Some (Apple) | Carrier retains all |
| Message backups | Encrypted, your key | Google/iCloud (unencrypted default) | Cloud, not E2E | iCloud | Carrier |
| Who owns your data | You | Meta | Telegram LLC | Apple | Carrier |
| Sealed sender | Yes | No | No | No | No |
| Note to self / secure notes | Yes | No | Yes | Yes | No |
Reproduced verbatim from The Privacy Diet, Chapter 5 — “Messaging: Why Signal”. The book explains the reasoning behind each verdict.