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Messaging

End-to-end encrypted messengers compared by how much metadata they expose: who you are, who you talk to, and when.

Last reviewed · 12 entries

Most mainstream messengers now offer end-to-end encryption (E2EE): only the people in a conversation can read the messages, not the company that carries them. That protects what you say. It does not hide who you are, who you talk to, when, how often and from where. That information is called metadata, and it is often enough to map someone’s relationships and routine without reading a single message.

This guide ranks messengers mainly by metadata exposure: whether you must hand over a phone number, who runs the servers, and what those servers can see and be forced to hand over. Encryption quality still matters, but among serious apps it is rarely the weakest link. Your device, your contacts and your own habits usually are, so read the tips section too.

At a glance

How verdicts work
ToolVerdictPlatforms
SimpleX ChatRecommended
BriarRecommended
MollyUse with caution
XMPP with OMEMOUse with caution
Delta ChatUse with caution
ThreemaUse with caution
CwtchUse with caution
SignalNot recommended
SessionNot recommended
Element (Matrix)Not recommended
TelegramNot recommended
WhatsAppNot recommended

What to look at before choosing

Three questions decide most of a messenger’s metadata exposure. What identifies you? A phone number links your account to a real-world identity in many countries, because many governments require ID to buy a SIM card. A random ID or no identifier at all does not. Who runs the network? A single company (centralised) can be served with one legal order and can go offline in one outage. A federated network (like email) spreads your data across several operators you may not know. A peer-to-peer network or a network of interchangeable relays has no central place where your contact list lives. What can the servers see? Even with E2EE, a server normally learns your IP address and who a message is going to, unless the design hides it.

AppYou sign up withWho runs the serversWhat the servers can learn
SimpleX ChatNothing: no account ID of any kindPreset relays by SimpleX Chat Ltd (UK) and Flux, or any relay you choose or hostEncrypted messages in queues not linked to any user ID; private routing hides your IP from destination relays
BriarNothing: the account exists only on your phoneNo servers; devices connect directly over Tor, Wi-Fi or BluetoothNo central operator to log anything
CwtchNothing: profiles are localNo central service; optional group servers anyone can runContacts connect through Tor onion services
Molly / SignalPhone number (number-free sign-up only in beta)Signal only (United States)Your IP address and the recipient of each message; sealed sender hides the sender
XMPP + OMEMOUsername at a server of your choiceAny provider, or your own serverYour server stores your contact list and sees presence and who you message, and when
Delta ChatRandom email address on a chatmail relayMany independent relays, or your ownSender and recipient addresses and message size
ThreemaRandom Threema IDThreema only (Switzerland)Centralised: one operator handles all traffic
SessionRandom key pairDecentralised network of independently run nodesOnion routing hides your IP from the nodes that store messages
Element (Matrix)Username on a homeserverAny homeserver, or your ownWho talks in which rooms, room names, reactions; copied to every participating server
TelegramPhone numberTelegram onlyNormal chats and groups are not end-to-end encrypted; metadata may be kept up to 12 months
WhatsAppPhone numberMeta onlyWho you talk to, when and how often, IP address and device details
Simplified; details and sources are in each app’s entry below.

Use with caution

Each of these is a reasonable choice for some people, but each has a specific weakness you should understand first: a phone-number-based network, server-side metadata, missing forward secrecy, a single company, or a small team.

Molly

Use with caution
Molly website (opens in a new tab)

Independent, hardened fork of the Signal app for Android. It talks to Signal’s servers and contacts, so it improves what is stored and exposed on your phone, not what Signal’s servers see.

Platform Support

AndroidOpen sourceEnd-to-end encrypted

Advantages

  • Encrypts the local database with a passphrase
  • Clears sensitive data from memory and can lock after inactivity
  • Can route traffic through Tor (Orbot) or a SOCKS proxy
  • Molly-FOSS build has no Google code; push via UnifiedPush or a direct connection

Drawbacks

  • Same phone-number requirement as Signal
  • Same centralised US servers and server-side metadata as Signal
  • Android only
  • UnifiedPush needs a MollySocket server and does not work on linked devices
  • You trust a small independent team with an app that holds your keys
  • Releases trail Signal’s: the latest (July 2026) is based on Signal 8.19
Molly source code and build flavoursMolly releases

XMPP with OMEMO

Use with caution
XMPP with OMEMO website (opens in a new tab)

XMPP is an open, federated chat standard that works like email: you pick a provider or run your own server and use any compatible app. OMEMO adds end-to-end encryption. Common clients: Conversations (Android), Monal (iOS, macOS), Gajim (Windows, macOS, Linux) and Dino (Linux).

Platform Support

WindowsmacOSLinuxAndroidiOSOpen sourceSelf-hostableNo phone number

Advantages

  • No single company; choose any provider or self-host
  • No phone number needed on most servers
  • Many open-source clients across all platforms
  • Self-hosting packages such as Snikket for families and small groups

Drawbacks

  • Your server stores your contact list and relays presence and messages
  • OMEMO spec: no protection against metadata and traffic analysis
  • OMEMO spec: only weak forward secrecy
  • Encryption defaults and OMEMO versions vary between clients
  • Group chats spread metadata across every participant’s server
OMEMO specification (XEP-0384), threat modelRFC 6121: the server stores your rosterWhich XMPP clients support OMEMOSnikket: self-hosted XMPP for small groups

Delta Chat

Use with caution
Delta Chat website (opens in a new tab)

Messenger that uses email as its transport. By default it creates a random address on a “chatmail” relay, so no phone number or real email is needed. Since version 2 (2025) chats are always end-to-end encrypted with OpenPGP; plain email appears only if you add a classic email account.

Platform Support

WindowsmacOSLinuxAndroidiOSOpen sourceSelf-hostableNo phone numberEnd-to-end encryptedAudited

Advantages

  • No phone number; random address created for you
  • Many independent relays, and you can run your own
  • Since 2026 nearly all headers are inside the encrypted part
  • Several independent audits, including ETH Zurich (2024)
  • Available on all major platforms

Drawbacks

  • No forward secrecy yet (planned with Autocrypt v2)
  • No post-quantum encryption yet
  • Relays see sender and recipient addresses and message size
  • No built-in Tor; the project suggests a system-wide VPN to hide your IP
Delta Chat FAQ: forward secrecy, metadata, auditsEncryption always on in Delta Chat v2 (2025)Metadata reduction in 2.48+ (2026)ETH Zurich analysis of SecureJoin (2024)Chatmail relays

Threema

Use with caution
Threema website (opens in a new tab)

Paid Swiss messenger that identifies you by a random Threema ID rather than a phone number. The apps are open source; the server software is not, and the public service is run only by Threema.

In January 2026 German private equity firm Comitis Capital agreed to buy Threema from Afinum and Threema’s founders. Threema says its management and mission are unchanged.

Platform Support

WindowsmacOSLinuxAndroidiOSWebOpen sourceNo phone numberEnd-to-end encryptedAudited

Advantages

  • No phone number or email required
  • One-time purchase; Android licence payable in cash via the Threema Shop
  • Open-source apps; reproducible builds on Android
  • Servers in Switzerland
  • Desktop app audited by Cure53 (2024)

Drawbacks

  • Centralised: a single company runs all servers
  • Server software is closed; self-hosting only via the business OnPrem product
  • Owned by private equity since 2020; sold to another fund in January 2026
  • ETH Zurich published seven attacks on its protocol (2023); Threema disputed the impact
  • Large DDoS attacks caused outages in August 2026
Comitis Capital acquires Threema (Privacy Guides)Comitis Capital announcement (January 2026)Threema audit listPay for Threema with cash (2023)ETH Zurich attacks on Threema’s protocol (BleepingComputer, 2023)DDoS outage report (August 2026)

Cwtch

Use with caution
Cwtch website (opens in a new tab)

Decentralised messenger from the non-profit Open Privacy Research Society. Every connection runs over Tor onion services and there is no central service; it is designed so that no server learns who talks to whom.

Platform Support

WindowsmacOSLinuxAndroidOpen sourceSelf-hostableNo accountNo phone numberEnd-to-end encrypted

Advantages

  • No phone number, account or central service
  • All communication over Tor v3 onion services
  • Anyone can run a server for group chats
  • Actively developed (1.17 in September 2026, 1.17.2 in October 2026)

Drawbacks

  • Small team funded by donations
  • Several features, including the new Hybrid Groups, are still experimental
  • 1.17.2 fixed several security bugs present in earlier releases
  • No iOS app
Cwtch 1.17.2 security and stability updateCwtch documentation

EU “Chat Control” and client-side scanning

Since 2022 the EU has been negotiating a Regulation to Prevent and Combat Child Sexual Abuse, which critics call Chat Control. The Commission’s original proposal would have let authorities order messaging providers, including end-to-end encrypted ones, to detect abuse material in private messages. For an E2EE app that in practice means client-side scanning: your own phone checks messages before they are encrypted and reports matches. Security researchers and digital-rights groups warn that encryption would then exist only on paper, because the app would contain a built-in inspection channel that could be misused, attacked or widened later.

  • November 2025: EU member states agreed a Council position that dropped mandatory detection orders but keeps “voluntary” scanning by providers as a permanent option.
  • December 2025 to now: Negotiations (trilogues) between Parliament, Council and Commission are ongoing. Parliament’s position allows only targeted scanning of suspects with a judicial warrant.
  • April 2026: According to Patrick Breyer’s tracker, the 2021 interim regulation that let providers scan private messages voluntarily expired on 4 April 2026 after Parliament rejected a second extension. Google, Meta, Microsoft and Snap say they continue scanning anyway.
  • June 2026: According to internal negotiation documents reported by netzpolitik.org, the institutions had provisionally agreed to keep encrypted content out of the regulation’s scope, which would rule out mandatory client-side scanning if it holds.
  • As of late October 2026: No final text has been adopted. The next trilogue, on 8 December 2026, is described as potentially final.

What this means for you: any scanning obligation would land on the companies that run messaging services for EU users. Peer-to-peer apps and servers you host yourself have no such company in the middle. Laws differ by country: Session’s former steward, for example, handed its role to a new Swiss foundation in 2024, citing the regulatory environment for encrypted messaging in Australia. Check the rules where you live.

Practical tips and common mistakes

Habits matter more than the app

  • Check who is in a group before you post. In March 2025 a US national security adviser accidentally added a journalist to a Signal group planning military strikes. Signal’s encryption worked; the problem was the member list. A December 2025 Pentagon inspector general report also faulted the defense secretary for sharing strike details from a personal phone.
  • Use only official apps or well-known forks. Weeks later the same adviser was photographed using TM SGNL, an unofficial Signal clone from TeleMessage that archives messages. In May 2025 TeleMessage was hacked and archived chats were stolen; the breach showed that messages were not end-to-end encrypted on their way to the archive.
  • Hide message content in notifications. In a case reported in 2026, the FBI recovered incoming Signal messages from an iPhone’s notification database even after the app had been deleted. Apple patched this in April 2026, but setting notifications to show no name or content is still the safer default on any phone.
  • Turn on disappearing messages for sensitive conversations, and remember that any recipient can still screenshot or photograph the screen.
  • Verify keys for important contacts. Compare safety numbers or scan QR codes in person once. This detects a server or attacker swapping keys.
  • Watch your backups. Cloud backups of chats can expose your whole history if they are not end-to-end encrypted. Check how your app backs up before you enable it.

Reduce what your account reveals

  • If an app needs a phone number, consider a separate number that is not linked to your name; see the telecom guide. Many countries require ID to buy a SIM card, so check what is legal where you live.
  • On Signal or Molly, set a username, set “Who can see my number” to Nobody and “Who can find me by number” to Nobody.
  • Hide your IP address from the servers you use with Tor or a trustworthy VPN; see the VPN guide. Briar has Tor built in, Molly can use Tor through Orbot, and SimpleX’s private routing already hides your IP from destination relays.
  • Strip metadata from photos and files before sending them; see the metadata guide.
  • Secure the device itself. A strong screen lock, full-disk encryption and prompt updates protect your messages more than any messenger feature; see the operating systems guide.

Further reading