How it compares

Swipe the table sideways to see every app.

1. Signal sends the numbers in your address book, encrypted, to a secure enclave on its servers whose code the app checks first, and states that the service learns nothing about what was asked (signal.org/blog/private-contact-discovery, 26 September 2017). CHANNEL uploads nothing from your address book.
2. 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.
3. 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. There are two exceptions. A phone’s long-lived prekey secret opens the first messages of a conversation that began from an invitation. And whoever holds the key two phones share from pairing can read the first messages the opening phone sends in each new session, until the other phone replies; it cannot forge them. The core both apps share is an independently developed cryptographic core implementing a Double Ratchet design based on Signal’s published specification, with CHANNEL-specific session establishment, recovery and post-quantum extensions. It has been tested with the test suites and fuzzing described on the Security page and reviewed by the outside AI models named there; no independent human audit has been done. Telegram does it in Secret Chats only. There is a plain-language explanation on the encryption page.
4. Sending over the internet is paid: two months free, then $4.99 a month or $49.99 a year, and on iPhone a family plan is $9.99 a month for up to six people through Apple Family Sharing, while on Android a subscriber can share the $4.99 plan with up to five paired contacts. Messaging over Bluetooth and Wi-Fi, and receiving everything anyone sends you, are free. WhatsApp and Telegram are free to use and funded another way. WhatsApp: funded by Meta, with ads in Status and Channels (CNBC, 16 June 2025) and business messaging. Telegram: Premium, Business, Stars and ads in large public channels (telegram.org/privacy, 5.6). Signal is a nonprofit funded by donations. Checked 22 October 2026.
5. Funding and retention rows checked on 22 October 2026 against each service’s own pages. CHANNEL: a mailbox holds a sealed one-to-one envelope until the other phone collects it, then forgets it; a formal group’s posts are kept, encrypted, for 30 days; mailbox addresses change every ten minutes and carry no name, phone number or account (see Security and Privacy). WhatsApp (whatsapp.com/legal/privacy-policy): uploaded address-book numbers, activity and last seen, device and connection details including IP, approximate location from IP and area code, information shared with other Meta companies, and information preserved and shared in response to legal process or government requests. Telegram (telegram.org/privacy, 3.3, 3.4, 5.2, 8.3): contacts (number and name) while synced, cloud messages stored encrypted on its servers (secret conversations are not), IP address and device metadata kept for at most 12 months if collected, and IP address and phone number disclosed to authorities on a valid court order. Signal (signal.org/bigbrother): in its published list of legal requests it could produce only the time an account was created and the last time it connected, and it states it holds no messages, calls, profile, group or contact data. These are what each company says it keeps and may be ordered to disclose, not a claim about what it has handed over.
6. WhatsApp, Reactions, 2GB File Sharing, 512 Groups, WhatsApp Blog: files within WhatsApp up to 2GB at a time. blog.whatsapp.com
7. Competitor cells checked on 5 October 2026 against WhatsApp’s blog and help pages, Signal’s support pages and blog, Telegram’s blog and published limits, and reporting on current limits. Group sizes: WhatsApp 1,024, Signal 1,000, Telegram 200,000. Post-quantum: Signal has published its post-quantum ratchet; no post-quantum message encryption announcement was found for WhatsApp or Telegram. Profiles: WhatsApp two accounts, Telegram three (four with Premium). Conversation lock: WhatsApp Chat Lock; Telegram offers an app passcode, not a lock on one conversation. Telegram’s view-once media is for private chats, and its 4 GB limit needs Premium. A tilde is partial, and the line under a tick says what it covers. Usernames: WhatsApp opened username reservations on 29 June 2026 and is rolling the feature out gradually; Signal and Telegram have them. Phone number: WhatsApp shows it to contacts until usernames reach an account; Signal hides it by default; Telegram’s visibility is a setting. Linked devices: WhatsApp 4, Signal 5, Telegram no stated limit; WhatsApp and Signal sign a linked device out when the phone has not connected for 14 and 30 days. Telegram’s ads are sponsored messages in public channels. Each platform sends one way, over the internet. AI: WhatsApp’s AI runs in Meta’s cloud, in a sealed environment it calls Private Processing; Telegram’s runs in its Cocoon network and with xAI’s Grok; Signal has none. Telegram’s Business chatbots, a Premium feature, let a bot reply for you in private chats; WhatsApp’s Business API is for business accounts. In CHANNEL, on-device AI uses Apple Intelligence, your own AI account is optional, and an AI on your Mac works only in the one profile you allow it, sends only CHANNEL messages to that profile’s contacts, and every request it makes is logged. Browser extensions: WhatsApp and Telegram run in a web browser (web.whatsapp.com, web.telegram.org), where any extension allowed to read pages can read the open conversation; Signal and CHANNEL have no web version.