CHANNEL| CHANNEL | Signal | Telegram | ||
|---|---|---|---|---|
| Works with no internet and no signal, when your contact is nearby | ✓ | — | — | — |
| Never sends your address book anywhere | ✓ | — | ~ | — |
| End-to-end encrypted by default | ✓ | ✓ | ✓ | — |
| No advertising identifiers or third-party tracking code | ✓ | — | ✓ | — |
| Keys that change with every message, so a stolen key cannot open old messages | ~ | ✓ | ✓ | ~ |
| Group chats | ~ | ✓ | ✓ | ✓ |
| Voice and video calls | ~ | ✓ | ✓ | ✓ |
| Desktop app | planned | ✓ | ✓ | ✓ |
| People you know are already on it | — | ✓ | ✓ | ✓ |
| Free | — | ✓ | ✓ | ✓ |
- Signal checks which of your contacts use Signal by sending scrambled forms of the numbers into sealed hardware, rather than uploading the book itself. Better than the others by a distance, but not nothing.
- Telegram encrypts ordinary chats between you and its servers, not end to end. Only its separate “Secret Chats” are end-to-end encrypted, and they are not the default.
- Forward secrecy: CHANNEL changes the message key as you go, as WhatsApp and Signal do, so a key taken from a phone opens little of what came before. It is our own implementation of Signal's published Double Ratchet, in the core both apps share, and it works between two phones that both have it; a message to a phone on an older build uses the key set at pairing. The tilde is because it has run between two test devices and not between two people's phones, and no outside cryptographer has reviewed it. Telegram does it in Secret Chats only. There is a plain-language explanation on the encryption page.
- CHANNEL is a paid app. Telegram and WhatsApp cost you nothing to use, so something other than you pays for them; that difference is the argument this whole page makes, and it is fair to hold us to the other side of it. Signal is the exception, and we said so above: a donation-funded nonprofit, free without selling anything.
Read the bottom rows again. We have no desktop app, groups that are not fully tested, and almost nobody on it. CHANNEL does place voice and video calls, sealed between the two phones like everything else, and a call rings a phone that is locked; that row is a tilde and not a tick because calls between two iPhones, or between two Android phones, are untested on real phones. Those are real reasons to keep using what you have, and we would rather you heard them from us. What the top of the table buys you is a conversation that never touches a company at all — and that is the only row we think is worth switching for.