Updated 2026-11-02
Which messaging app is most secure?
It depends on what you need to protect, and the honest answer names more than one app.
Signal is the strongest widely used messenger, with years of audits and post-quantum protection, but standard sign-up still needs a phone number. SimpleX needs no identifier at all. Session hides your IP address through its own network but currently lacks forward secrecy. Dead Safe combines no identifiers, post-quantum key agreement, cash payments and a second profile for forced unlocks, and proves each claim with a public test; it has not yet had an independent audit.
Side by side
| Checked 2026-11-02 | Signal | SimpleX | Session | Threema | WhatsApp | Telegram | Dead Safe |
|---|
| End-to-end encrypted by default | Yes | Yes | Yes | Yes | Yes | No (opt-in “secret chats”, one-to-one only) | Yes |
|---|
| Phone number needed to sign up | Yes (numberless sign-up in beta, Sep 2026) | No | No | No | Yes | Yes | No |
|---|
| Permanent account identifier | Phone number, optional username | None | Random account ID | Threema ID | Phone number | Phone number, optional username | None |
|---|
| Forward secrecy | Yes | Yes | No (removed 2021; v2 in development) | Yes (Ibex protocol; initially opt-in per contact) | Yes | Secret chats only | Yes |
|---|
| Post-quantum key agreement | Yes (PQXDH 2023, plus post-quantum ratchet 2025) | Yes (direct chats, since 2024) | No (planned in v2) | No (stated goal) | Unclear (no official confirmation found) | Not announced | Yes (hybrid, at connection and on every reply) |
|---|
| Hides your IP address from its servers | No | Partly (private message routing; Tor optional) | Yes (onion-routed network) | No | No | No | Not yet (Tor planned) |
|---|
| Price | Free (donations) | Free | Free (Pro tier in beta) | Paid app | Free | Free (Premium tier) | Free; Pro payable by cash in the post |
|---|
| Second profile for forced unlocks | No | Hidden profiles | No | No | No | No | Yes |
|---|
| Independent security audit | Yes | Yes | Yes | Yes | Not assessed here | Not assessed here | No (planned before 1.0) |
|---|
Sources
- Signal: Quantum resistance and the Signal Protocol (2023)
- Signal: Signal Protocol and Post-Quantum Ratchets (Oct 2025)
- Signal: Keep your phone number private with usernames (2024)
- Privacy Guides: Signal enables phone-number-less registration in beta (Sep 2026)
- SimpleX: protocol overview
- SimpleX v5.7: quantum-resistant encryption by default in direct chats (Apr 2024)
- Session: Protocol V2, PFS and post-quantum (2025)
- Privacy Guides: Session adds PFS, PQE and other improvements (Dec 2025)
- Threema: New communication protocol "Ibex"
- Kaspersky: Telegram and secret chats
Which one fits you
You want strong security that your friends already use
Signal. It is free, open source, has had independent audits, and is post-quantum protected. Hide your number from contacts with a username, and watch for its numberless sign-up leaving beta.
You don't want any identifier linked to you
SimpleX or Dead Safe. Neither needs a phone number, email or username, and neither gives you a permanent account ID on its servers. Dead Safe adds anonymous cash payment, a second profile for forced unlocks and a test for every claim; SimpleX has a longer track record and independent audits today.
You need to hide your IP address from the servers
Session routes traffic through its own network, though it currently lacks forward secrecy. Alternatively, use SimpleX over Tor. Dead Safe does not hide your IP address yet; built-in Tor routing is planned.
You are using WhatsApp or Telegram
WhatsApp encrypts content well but requires a phone number and is owned by a company whose business is data. Telegram's normal chats and all its group chats are not end-to-end encrypted.
About Dead Safe
Everything we claim, with the test that proves it, is on the security page, together with 14 published limitations. If you find a claim on this site that our code doesn't back up, that is a bug, and we want to hear about it.
When can I use it?