Signal vs SimpleX vs Briar vs Session: Private Messaging Apps Compared (2026)
A deep-dive comparison of the four leading private messengers — Signal, SimpleX, Briar, and Session — covering encryption protocols, metadata exposure, platform support, and real-world usability on GrapheneOS and beyond.
TL;DR: Signal is the most polished private messenger and easiest to recommend broadly. SimpleX eliminates all user identifiers and decentralizes relays. Briar works peer-to-peer — even offline over Bluetooth — but lacks iOS. Session offers onion-routed, phone-number-free messaging and is re-adding forward secrecy in Protocol V2. All four are legitimate tools with different trade-offs; many privacy-conscious users run two or more.
Choosing a private messenger in 2026 is no longer a question of “Signal or nothing.” (If you’re still setting up your device, start with our privacy phone setup guide it includes a practical app stack.) A new generation of apps pushes different boundaries of privacy, metadata resistance, and censorship resilience — and the “best” one depends on your threat model.
In this guide, we compare four leading contenders — Signal, SimpleX, Briar, and Session — covering encryption, metadata, daily usability, and GrapheneOS compatibility.
1. Signal — The Gold Standard
How It Works
Signal uses the Signal Protocol — the Double Ratchet Algorithm combined with X3DH key agreement and AES-256 symmetric encryption. Every message gets a unique key, providing both perfect forward secrecy and future secrecy (post-compromise security).
Architecturally, Signal is centralized: all messages pass through Signal Foundation servers, but those servers are designed to know as little as possible. Sealed Sender encrypts the sender’s identity so even Signal’s servers cannot see who is messaging whom.
Metadata Exposure
Signal has been subpoenaed multiple times. Each time, the only data produced was: the date an account was created and the date it last connected. No message contents, contact lists, group memberships, or call records. Sealed Sender further reduces transport-layer metadata, though a sufficiently motivated adversary could still perform traffic analysis.
Signal requires a phone number to register. You can now set a username and hide your number from contacts, but the phone number remains the underlying account identifier.
User Experience
Signal is the most mature app in this comparison. Setup takes under a minute: install, verify your phone number, and go. The interface is clean and familiar — it will feel natural to anyone coming from WhatsApp or iMessage.
- Group chats: Up to 1,000 members with full E2EE. Admin controls, mention support, disappearing messages.
- Calls: Encrypted voice and video calls, including group calls with up to 40 participants (recently expanded toward 75 in testing). Call quality is excellent over decent connections.
- File sharing: Images, video, documents, and voice messages. Signal strips EXIF metadata from photos by default.
- Extras: Stories, stickers, note-to-self, secure cloud backups (launched in 2025 for Android and iOS), message formatting.
Platform Support
Android, iOS, Windows, macOS, Linux. The desktop app links to your phone but can operate independently after initial setup. All platforms stay in tight sync.
Funding & Governance
Signal is developed by the Signal Technology Foundation, a US-based 501(c)(3) nonprofit. It is primarily funded by donations, with a major early grant from Brian Acton (WhatsApp co-founder), who donated $50 million. Annual operating costs were estimated at approximately $50 million for 2025. Signal accepts no advertising or venture capital and has no investors to answer to.
Known Limitations
- Phone number requirement links your account to a real-world identifier.
- Centralized infrastructure creates a single point of failure and government pressure.
- Blocked in several countries; circumvention is supported but remains an ongoing effort.
GrapheneOS Compatibility
Signal works excellently on GrapheneOS (see our GrapheneOS beginner’s guide and setup guide). It is available from the Play Store via the sandboxed Google Play compatibility layer, from Aurora Store, or via Signal’s own APK. Push notifications work through Google Play Services if installed in the sandbox, or Signal can fall back to its own WebSocket-based notification system — ideal for a fully de-Googled setup. Battery usage is slightly higher with WebSocket polling, but it’s a well-optimized implementation.
2. SimpleX — No Identifiers, Period
How It Works
SimpleX Chat takes a radical approach: there are no user identifiers at all. No phone number, no email, no username, no persistent public key as identity. Users connect through one-time or reusable invitation links and QR codes. Each contact relationship uses its own pair of unidirectional messaging queues routed through separate relay servers.
Encryption uses a double-ratchet protocol similar to Signal’s, with an added per-message encryption layer. As of 2025, SimpleX implements quantum-resistant encryption for one-to-one chats, groups, and calls.
The architecture is decentralized: anyone can run an SMP (SimpleX Messaging Protocol) relay server. Because each conversation routes through different relays, no single server sees your full social graph.
Metadata Exposure
Because there are no user IDs, there is no social graph to subpoena. SimpleX relay servers cannot correlate senders and recipients across conversations — each connection uses separate, unlinked queues. Servers see encrypted blobs with no way to associate them with a persistent identity.
The trade-off: you must exchange an invitation link or QR code out-of-band to start any conversation. There’s no way to “look someone up.”
User Experience
SimpleX has matured rapidly but still feels more “privacy tool” than “mainstream messenger.”
- Setup: No registration. Open the app, optionally set a display name, and share a link or QR code to connect.
- Group chats: “Secret groups” with E2EE. Works well for small to medium sizes; best for dozens of members, not hundreds.
- Calls: Encrypted voice and video calls supported, though quality is still maturing.
- File sharing: Images, files, and voice messages with E2EE.
Platform Support
Android, iOS, Windows, macOS, Linux. The desktop apps are full-featured and can operate independently. Multi-device sync has been implemented, though the experience is still evolving. SimpleX is also available as a terminal/console application for advanced users.
Funding & Governance
SimpleX Chat Ltd is a UK-registered company. Funding includes $1.3 million pre-seed led by Jack Dorsey (August 2024), with Asymmetric Capital Partners and Village Global. In November 2025, Vitalik Buterin donated 128 ETH. User donations contribute to infrastructure. Fully open-source under AGPL.
Known Limitations
- No user directory means contact discovery requires out-of-band sharing.
- Group scalability is limited compared to centralized systems.
- Most traffic currently flows through default SimpleX-operated relays, though self-hosting is straightforward.
- Blocked in Russia since 2024; SimpleX Chat Ltd was fined by a Moscow court in 2025 for refusing to hand over encryption keys.
- Some extremist groups migrated to SimpleX after Telegram crackdowns — reflecting strong privacy properties, not a design flaw.
GrapheneOS Compatibility
SimpleX runs perfectly on GrapheneOS. It is available on F-Droid and as a direct APK download from GitHub, making it ideal for fully de-Googled setups. It does not require Google Play Services for notifications — it uses its own background connection. Battery usage is reasonable with modern Android battery optimization.
3. Briar — The Mesh Messenger
How It Works
Briar is architecturally unique: a true peer-to-peer messenger with no servers. Messages transmit directly between devices via:
- Tor hidden services — each device runs a Tor onion service for direct peer connections.
- Wi-Fi Direct — devices on the same local network sync without internet.
- Bluetooth — devices in proximity exchange messages with no network at all.
Briar uses the Bramble protocol suite, built for delay-tolerant networking. Messages are stored encrypted on-device and synced when peers connect. Key exchange happens via in-person QR scanning or mutual introductions.
Metadata Exposure
Briar’s metadata profile is the strongest here. No servers to subpoena. Tor hides IP addresses; Bluetooth/Wi-Fi produces no network traffic to intercept. No accounts, no phone numbers, no directory. The only observable metadata is Tor traffic patterns from your device, and onion services make correlation harder than standard Tor use.
User Experience
Briar prioritizes security and resilience over convenience, and it shows.
- Setup: Create a local account with a username and password. No phone number or email. To add contacts, you must either meet in person and scan QR codes, or receive an introduction from a mutual contact. There is no “search by username” feature.
- Group chats: Supported but designed for small groups. Briar also includes forums (public groups) and blogs within the app.
- Calls: Not supported. Briar is text and images only.
- File sharing: Images and small files; not designed for large transfers.
- Offline messaging: Briar’s killer feature. Messages queue and deliver whenever devices reconnect — via Tor, Wi-Fi, or Bluetooth. In protests, disaster zones, or network shutdowns, Briar keeps working.
Platform Support
Android is the primary and most mature platform. A desktop client (Windows, macOS, Linux) exists but is in beta and offers reduced functionality. There is no iOS app, and the Briar developers have stated they have no plans to create one — Apple’s restrictions on background processes and direct device-to-device communication make a full-featured Briar implementation impractical on iOS.
Funding & Governance
Briar is developed by the Briar Project, a volunteer-driven open-source effort. It has received funding from the Open Technology Fund (over $361,000 as of 2018) and operates as a community project. The code is licensed under GPL-3.0.
Known Limitations
- No iOS support — a dealbreaker for many.
- No voice or video calls.
- Desktop client is in beta.
- Both contacts must be online simultaneously for delivery — no server-side queuing.
- Adding contacts requires QR scanning or mutual introductions.
- Higher battery consumption from Tor and Bluetooth.
GrapheneOS Compatibility
Briar works well on GrapheneOS and is available on F-Droid and via direct APK, requiring no Google Play Services whatsoever. It runs entirely self-contained. Battery consumption is the main concern — Briar maintains persistent Tor and Bluetooth connections that draw more power than typical messaging apps. GrapheneOS’s per-app battery controls can help manage this.
4. Session — Onion-Routed and Decentralized
How It Works
Session began as a fork of Signal in 2020, eliminating the phone number requirement and centralized infrastructure. Messages route through an onion network — originally Lokinet/Oxen, and since May 2025, the dedicated Session Network — bouncing through multiple nodes so no single one knows both sender and recipient.
Session uses its own Session Protocol for encryption. After forking from Signal, it removed forward secrecy in 2021 for decentralized infrastructure compatibility — the project’s most controversial decision. In late 2025, Session announced Protocol V2, re-introducing Perfect Forward Secrecy alongside post-quantum encryption.
Accounts use a 66-character Session ID (a public key). No phone number or email required.
Metadata Exposure
Session’s onion routing provides strong metadata protection. Messages bounce through three nodes (a “swarm”), so no individual node sees both sender and recipient. The Session Network uses staking (operators must stake cryptocurrency) as Sybil resistance.
Session’s no-logging policy (January 2026) states it does not log IP addresses. However, the current protocol’s lack of forward secrecy means a compromised long-term key could decrypt past messages — a gap Protocol V2 aims to close.
User Experience
Session feels polished and closer to Signal’s UX than Briar or SimpleX.
- Setup: Generate a Session ID with one tap. Back up your recovery phrase. No phone number or email.
- Group chats: Closed groups up to 100 members with E2EE. Open groups (public channels) available but without E2EE.
- Calls: Voice and video, onion-routed. Quality can be variable due to multi-hop latency.
- File sharing: Images, files, voice notes, video — all encrypted.
Platform Support
Android, iOS, Windows, macOS, Linux. Full cross-platform coverage. Multi-device linking is supported, and the Protocol V2 announcement describes improved device synchronization.
Funding & Governance
Originally developed by the Oxen Privacy Tech Foundation in Australia. In 2024, facing restrictive surveillance legislation, the project moved to Switzerland under the Session Technology Foundation, a nonprofit. Infrastructure is funded through the SESH token (migrated from OXEN in May 2025). Vitalik Buterin donated to Session in November 2025.
Known Limitations
- Current Session Protocol (V1) lacks forward secrecy — the most significant security criticism. Protocol V2 is under development but not yet deployed.
- Cryptocurrency-incentivized network is controversial; ties infrastructure to crypto-economic dynamics.
- Onion routing adds latency to messages and calls.
- Some centralization concerns around node distribution.
- Smaller group sizes than Signal.
GrapheneOS Compatibility
Session runs well on GrapheneOS. It is available via F-Droid and as a direct APK download — no Google Play Services required. Push notifications can work via Google Play Services if sandboxed, or Session uses background polling without them. The app is well-behaved in terms of battery usage on GrapheneOS.
Comparison Table
| Feature | Signal | SimpleX | Briar | Session |
|---|---|---|---|---|
| Encryption Protocol | Signal Protocol (Double Ratchet) | SimpleX Protocol (Double Ratchet + per-message layer) | Bramble Protocol Suite | Session Protocol (V2 planned) |
| Forward Secrecy | ✅ Yes | ✅ Yes | ✅ Yes | ❌ No (V2 will restore it) |
| Post-Quantum Encryption | 🔄 In progress (PQXDH) | ✅ Yes | ❌ No | 🔄 Planned (V2) |
| User Identifier | Phone number | None | Local username | 66-char Session ID |
| Phone Number Required | ✅ Yes | ❌ No | ❌ No | ❌ No |
| Network Architecture | Centralized servers | Decentralized relays (federated) | Peer-to-peer (Tor / Bluetooth / Wi-Fi) | Onion-routed, decentralized (Session Network) |
| Metadata Resistance | Good (Sealed Sender) | Excellent (no user IDs, split relays) | Excellent (no servers) | Very Good (onion routing) |
| Voice/Video Calls | ✅ (up to 40–75 participants) | ✅ (1:1) | ❌ No | ✅ (1:1, onion-routed) |
| Max Group Size | 1,000 | ~Dozens (practical limit) | Small groups | 100 (closed) |
| Offline / Mesh Messaging | ❌ No | ❌ No | ✅ Yes (Bluetooth/Wi-Fi) | ❌ No |
| Android | ✅ | ✅ | ✅ | ✅ |
| iOS | ✅ | ✅ | ❌ No (no plans) | ✅ |
| Desktop | ✅ | ✅ | ✅ (beta) | ✅ |
| Open Source | ✅ | ✅ (AGPL) | ✅ (GPL-3.0) | ✅ (GPL-3.0 / BSD-3) |
| Works Without Google Play | ✅ (WebSocket fallback) | ✅ | ✅ | ✅ |
| Governance | US nonprofit | UK company | Community project | Swiss nonprofit |
Which Should You Use?
There’s no single “best” private messenger — it depends on your threat model. Here’s a decision framework:
You want the strongest all-around messenger for daily use
→ Signal. It has the best encryption, the most polished UX, the largest user base, and the most battle-tested track record. If you can accept the phone number requirement (mitigated with a secondary number or VoIP), Signal is the standard for a reason.
You want to eliminate metadata and identifiers entirely
→ SimpleX. No user IDs, no phone number, decentralized relays, quantum-resistant encryption. SimpleX is the strongest choice when your threat model includes social graph analysis or when you cannot afford any account identifier to exist.
You need to communicate without any internet infrastructure
→ Briar. If you’re in a protest environment, a disaster zone, or a country with internet shutdowns, Briar’s ability to work over Bluetooth and Wi-Fi with no servers is unmatched. Its requirement for Android-only and in-person contact exchange reflects a fundamentally different use case.
You want phone-number-free messaging with onion routing and broad platform support
→ Session. Session occupies a middle ground: easier to use than Briar, more anonymous than Signal, and available on iOS (unlike Briar). The lack of forward secrecy in the current protocol is a real concern, but Protocol V2 is actively in development. If onion routing and anonymity matter more to you than cryptographic perfection today, Session is a strong contender.
Can You Use Multiple? (Yes — You Should)
Using more than one private messenger is not only acceptable, it’s often the smartest approach. A practical strategy:
- Signal for your everyday contacts — family, friends, colleagues who won’t install a niche app. Signal is “good enough” privacy for the vast majority of conversations and easy enough to replace WhatsApp.
- SimpleX for your most privacy-sensitive conversations — sources, activists, anyone where you need zero metadata and no account linkability.
- Briar as an emergency tool — pre-installed on your phone and your closest contacts’ phones in case the internet goes down.
- Session as an anonymous contact channel — where you want to give out a public contact ID without revealing a phone number.
Each app fills a different niche. They complement rather than compete.
The WhatsApp & Telegram Elephant in the Room
Let’s be honest about why most people haven’t switched: network effects are incredibly powerful. Your group chats are on WhatsApp. Your family is on WhatsApp. Your kid’s school uses WhatsApp. Telegram has the channels you follow. Moving billions of people is a slow process.
Why People Stay
- Everyone’s already there. Messaging apps are only useful if your contacts use them too.
- “Good enough” thinking. WhatsApp does have E2EE for message content (using the Signal Protocol, ironically). Many people equate this with “private,” not understanding that WhatsApp still collects extensive metadata — who you talk to, when, how often, your location, device info, and more — and shares it with Meta.
- Feature completeness. WhatsApp and Telegram offer payments, business accounts, channels, bots, and ecosystem integrations that privacy-focused apps don’t.
How to Actually Migrate Contacts
Don’t try to convert everyone at once. The strategy that works:
- Install Signal yourself. It will show you which contacts already have it — you may be surprised.
- Start using it with willing contacts. Don’t preach; just say “I prefer Signal, here’s my link.”
- Create a Signal group for your closest circle — family, close friends — and make it the default venue.
- Keep WhatsApp installed for the holdouts, but shift your active conversations gradually.
- For privacy-sensitive contacts, introduce them to SimpleX or Session with a shared invitation link. Frame it as “this one doesn’t need a phone number.”
The key insight: you don’t have to delete WhatsApp to improve your privacy. Every conversation you move to Signal (or beyond) is a conversation Meta can no longer mine.
Final Thoughts
Signal remains the recommendation for most people — private, polished, and proven. But for higher threat models, SimpleX, Briar, and Session each push boundaries Signal cannot or chooses not to. The best messenger is the one your contacts will actually use. The second best is the one that matches your threat model.
Related Guides
- How to Set Up a Privacy Phone in 2026
- Best VPNs for Privacy Phones in 2026
- Whats Your Threat Model? (Framework)
- What Is GrapheneOS? (Beginners Guide)
Stay private out there.