Signal vs SimpleX vs Session: Which Is Most Private?

At a glance

What each messenger still reveals. Registration and delivery-path differences between four end-to-end encrypted messengers.

Sources

1. 1. support.signal.org · 6712070553754 Phone Number Pr…
2. 2. simplex.chat · simplex
3. 3. docs.getsession.org · session protocol.md
4. 4. spec.matrix.org · v1.19

Data behind this diagram

Registration and delivery-path differences between four end-to-end encrypted messengers.

App	phone at signup	global identifier	delivery path	main limit
SIGNAL	required	phone account + optional username	central delivery service	number still required at registration
SIMPLEX	no	none — no global user id	separate relay queues, self-hostable	invitation links are credentials
SESSION	no	random account id	onion-routed, distributed storage	no forward secrecy in current protocol
MATRIX	varies by homeserver	user id on a homeserver	federated homeservers	servers process account + room state

Scroll →

Signal is the strongest default for most people. SimpleX removes a global account identifier. Session removes phone registration but has a different key and recovery model. Matrix is useful for federated groups, but its privacy depends on the client, room settings, and homeservers.

Encryption protects message content in transit. It does not erase account identifiers, discovery records, delivery metadata, backups, linked devices, or readable data on an unlocked phone. This comparison covers those boundaries for Signal, SimpleX, Session, Matrix, Molly, Briar, Cwtch, and Ricochet Refresh.

01

Choose by need

Everyday defaultSignalMature encrypted calls, groups, and linked devices.No global addressSimpleX ChatEach contact uses separate invitation and relay queues.No phone registrationSessionAn Account ID and routed requests replace the phone number.Works without internetBriarDirect Bluetooth, Wi-Fi, or Tor connections.

02

Identity and network comparison

Names open official sites. Service details are linked where available.

Messaging identity, discovery, metadata path, and server trust

App	Identifier and phone	Discovery and metadata path	Best for
Signalsignal.org	Identifier▲Phone: RequiredPhone account; optional username for discovery	Discovery / Metadata path / Server trustNumber, exact username, link, or QRCentral delivery service; message content is end-to-end encrypted	Best forPrivate everyday messaging
SimpleX Chatsimplex.chatService details	Identifier■Phone: NoNo global user identifier	Discovery / Metadata path / Server trustOne-time or reusable invitation linkSeparate encrypted relay queues; relays can be self-hosted	Best forContacts without a platform-wide address
Sessiongetsession.orgService details	Identifier■Phone: NoRandom Account ID	Discovery / Metadata path / Server trustAccount ID, QR, or communityOnion-routed requests and distributed message storage	Best forPhone-free messaging with routed requests
Matrixmatrix.org	Identifier△Phone: VariesUser ID on a homeserver	Discovery / Metadata path / Server trustUser ID, room invite, or optional identity serviceFederated homeservers process account and room state	Best forFederated groups, teams, and communities
Mollymolly.im	Identifier▲Phone: RequiredSignal account; optional Signal username	Discovery / Metadata path / Server trustSignal discovery modelSignal network with extra Android storage controls	Best forSignal on Android with a locked local database
Briarbriarproject.orgService details	Identifier■Phone: NoLocal profile joined through contact exchange	Discovery / Metadata path / Server trustIn-person QR or invitation linkDirect Tor, Wi-Fi, or Bluetooth; optional owned Mailbox	Best forOffline and censorship-resistant messaging
Cwtchcwtch.im	Identifier■Phone: NoPublic-key profile	Discovery / Metadata path / Server trustInvitation or shared contact addressTor peer connections; group design changes the trust boundary	Best forTor-based peer and small-group messaging
Ricochet Refreshricochetrefresh.net	Identifier■Phone: NoTor onion service address	Discovery / Metadata path / Server trustShare the address through another channelDirect Tor onion connection between contacts	Best forFocused desktop chat without a central account

Scroll →

03

Features and setup

Messaging calls, groups, platforms, offline use, and self-hosting options

App	Calls	Groups	Platforms	No internet	Run your own
Signal	CallsVoice + video	GroupsChats + calls	PlatformsMobile + desktop	No internetNo	Run your ownNo
SimpleX ChatService details	Calls1:1 audio + video	GroupsChats; no group calls	PlatformsMobile + desktop	No internetNo	Run your ownRelays + TURN
SessionService details	Calls1:1 beta	GroupsPrivate groups	PlatformsMobile + desktop	No internetNo	Run your ownCommunities only
Matrix	CallsClient-dependent	GroupsRooms	PlatformsClient-dependent	No internetNo	Run your ownHomeserver
Molly	CallsSignal calls	GroupsSignal groups	PlatformsAndroid	No internetNo	Run your ownNo
BriarService details	CallsNo	GroupsGroups + forums	PlatformsAndroid	No internetBluetooth + Wi-Fi	Run your ownMailbox
Cwtch	CallsNo	GroupsExperimental	PlatformsDesktop + Android	No internetNo	Run your ownGroup server
Ricochet Refresh	CallsNo	GroupsNo	PlatformsDesktop	No internetNo	Run your ownPeer-to-peer

Scroll →

04

Backup, recovery, and device access

Messaging backup and seized-device comparison

App	Backup or recovery	Multi-device	If a device is seized
Signal	Backup or recoveryEncrypted backup or device transfer; separately protected	Multi-deviceLinked devices keep their own local history	If a device is seizedUnlocked app data and linked-device history
SimpleX ChatService details	Backup or recoveryEncrypted local export and client transfer	Multi-deviceAdditional profiles and devices need deliberate setup	If a device is seizedLocal database and notification content
SessionService details	Backup or recoveryRecovery password restores the account and limited recent state	Multi-deviceDevices share account keys and state	If a device is seizedRecovery material or unlocked local data
Matrix	Backup or recoveryKey backup depends on the client and homeserver	Multi-deviceEvery verified session can receive room keys	If a device is seizedLocal stores, exported keys, and authorized sessions
Molly	Backup or recoverySignal transfer rules; optional local passphrase	Multi-deviceUses Signal linked devices	If a device is seizedPassphrase protection helps only while the app is locked
BriarService details	Backup or recoveryManual encrypted app backup	Multi-deviceNo general synchronized multi-device account	If a device is seizedLocal database and any unlocked paired Mailbox
Cwtch	Backup or recoveryManual password-protected profile export	Multi-deviceImported profiles are not live synchronization	If a device is seizedProfile files and unlocked local conversations
Ricochet Refresh	Backup or recoveryLocal desktop profile	Multi-deviceNo synchronized multi-device account	If a device is seizedCopied or unlocked profile, contacts, and local history

Scroll →

05

Set up the leading options

Signal

Phone: Required

Install

1. 01

   Install the mobile app and register a phone number. Link desktop devices only after the phone works.

2. 02

   Open Settings, Privacy, Phone Number. Set number visibility to Nobody. Set discovery to Nobody if you will share a username instead.

3. 03

   Enable Registration Lock, verify important contacts, and remove any linked device you do not control.

Signal privacy settings

SimpleX Chat

Phone: No

Install

1. 01

   Install the official app and create a local profile. No phone number or email is required.

2. 02

   Create a one-time invitation link for the first contact. Confirm the security code after connecting.

3. 03

   Protect the local database, hide notification previews, and use Tor or transport isolation when network linkage matters.

SimpleX privacy settings

Session

Phone: No

Install

1. 01

   Install Session and create an Account ID. A phone number and email address are not required.

2. 02

   Write the Recovery Password down and keep it offline before adding important contacts.

3. 03

   Exchange the Account ID or QR through another channel. Review connected devices and call settings before use.

Session recovery instructions

Matrix

Phone: Varies

Install

1. 01

   Choose a maintained client and homeserver. Check the homeserver policy before creating the account.

2. 02

   Create a private room with end-to-end encryption enabled. Set up Secure Backup and store its Security Key offline.

3. 03

   Verify every new session. Review room members, bridges, bots, and participating homeservers before sharing sensitive material.

Matrix private-room setup

A strong device passcode, current operating system, hidden notification previews, short local retention, and a review of linked sessions matter across every app. For the separate extraction threat, see what phone extraction tools target.

Telegram is not an equivalent default

Telegram describes itself as a cloud messaging service. Its privacy policy distinguishes cloud chats from end-to-end encrypted Secret Chats and says cloud chat content is stored on Telegram's servers for cross-device access. Do not treat an ordinary Telegram chat or group as equivalent to Signal's default end-to-end encryption.

Controls that matter on every app

• Verify contacts or devices through a second channel.
• Remove linked devices you no longer control.
• Lock the app and encrypt the device.
• Disable message previews on the lock screen.
• Install updates from the official project or app store.
• Assume the recipient can copy anything they receive.

Malware can read messages on screen or capture them before encryption. A hidden camera, notification preview, cloud device backup, or cooperating contact can do the same. Messenger choice narrows exposure. It does not replace endpoint security.

Sources

• Signal downloads
• Signal Support: phone number privacy and usernames
• Signal Support: backups and device transfers
• Signal Support: linked devices
• Signal Support: group calls
• Signal: published government requests
• SimpleX platform design
• SimpleX downloads
• SimpleX privacy and security settings
• SimpleX audio and video calls
• Session protocol documentation
• Session installation
• Session account restoration
• Session calls and groups
• Matrix end-to-end encryption guide
• Matrix private-room setup
• Matrix specification 1.19
• Matrix hosting options
• Molly features
• Molly: data encryption at rest
• Briar: how it works
• Briar groups and offline use
• Cwtch security components
• Cwtch groups and server experiment
• Ricochet Refresh stable release
• Telegram privacy policy

Reviewed 22 Aug 2026. Cunicula receives no funding from the projects named in this comparison.