SimpleX Chat: messaging without an account, phone number, or identity
Signal is better than WhatsApp. That’s true. But Signal has one blind spot: you need a phone number to register, and that number is tied to your identity.
SimpleX Chat: messaging without an account, phone number, or identity
Signal is better than WhatsApp. That’s true. But Signal has one blind spot: you need a phone number to register, and that number is tied to your identity.
Signal now hides your number from other users. But the number itself remains the key Signal uses to know who you are. If Signal receives a legal demand, they know your registration number, when you last connected, and from which IP address.
SimpleX approaches this differently. Not by hiding your number — but by not requiring any identifier at all.
Who this guide is for
This guide is mainly for readers who have a concrete reason not to expose a phone number, account ID, or stable identifier in messaging.
It fits especially:
- journalists, activists, or sources where identifier-free contact matters
- stalking or abuse contexts where a phone number itself creates risk
- readers who already understand that this is not a mainstream messenger convenience play
For most normal readers, Signal is still the better default. SimpleX becomes the right tool when “no phone number” is a requirement, not just an interesting feature.
What you gain, and what it costs
If you use SimpleX, you usually gain:
- messaging without a phone number, username, or central account
- less centrally requestable account metadata
- stronger separation from the identity model used by mainstream messengers
But it costs something:
- more friction when starting contact
- less recoverability and less social convenience
- a smaller ecosystem than Signal or WhatsApp
For the right profile that is a reasonable trade. It becomes overkill when you mainly want a better WhatsApp replacement for everyday use and do not have a concrete identifier problem to solve.
No account, no identifier
This is the fundamental difference.
Every messaging app you’ve ever used — WhatsApp, Signal, Telegram, iMessage, Matrix — links your messages to an identifier. A phone number, a username, an email address, an account ID. That identifier exists on a server somewhere. That’s where someone can find you, request your data, or subpoena records.
SimpleX works differently. There is no identifier. No account. No registration.
Instead, SimpleX uses message queues: temporary addresses you create and share. When someone wants to message you, they post to your queue. You read from the queue. The server only sees: “someone placed something in this queue” — not who the sender is, not who the receiver is, and not what the message contains.
SimpleX is designed so relay servers do not have a central user register or contact graph. That makes legal requests and large-scale metadata analysis much harder, but it is not a magical shield against every kind of traffic analysis. The project itself recommends Tor if you also want to hide your IP address better.
How the encryption works
SimpleX uses the Signal Protocol for end-to-end encryption of message content — the same protocol as Signal and WhatsApp. Each conversation has unique keys. Messages are encrypted on your device and decrypted only on the recipient’s device.
On top of that, SimpleX uses continuous post-quantum key exchange in newer versions. That is meant as extra protection for future attacks on key exchange.
The relay servers that forward messages see encrypted packets and do not have a global user ID to tie conversations to. They still see network traffic. If you also want to hide your IP address from the servers, use Tor.
What this protects compared to Signal
| Signal | SimpleX | |
|---|---|---|
| Message content | Encrypted | Encrypted |
| Phone number required | Yes | No |
| Servers know your identity | Yes (number) | No |
| Servers see who talks to whom | No (Sealed Sender) | No central contact ID, but traffic analysis remains possible |
| Legally compellable data | Number + last connection | No central account ID; limited server and network metadata may still exist |
| Post-quantum encryption | No | Yes (newer versions) |
Signal’s Sealed Sender hides extra metadata, but Signal still knows your registration number. SimpleX keeps no central account or phone number, so there is less directly requestable account metadata. That does not mean all network traces disappear.
Installing and getting started
SimpleX is available for Android, iOS, and desktop (Linux, macOS, Windows).
Android: via Google Play, the SimpleX website, F-Droid.org, or the official SimpleX F-Droid repository. On GrapheneOS, F-Droid or the official repo is usually the sensible route.
iOS: via the App Store.
Desktop: download from simplex.chat.
On first launch, no registration is required. You create a local chat profile with a display name. That profile is not stored on a central server.
Making contact
There is no search function. You cannot find anyone by name or phone number — because that identifier doesn’t exist.
Contact is made via an invitation link or QR code. You generate a link, share it, the other person clicks it. That establishes the connection.
Go to New conversation → Create invitation link. Share the link via any channel — Signal, email, in person. Once used, the link is consumed.
You can also create a SimpleX address: a reusable link you can share publicly (on a website, contact page, or business card). New connections via this address require your approval before they can message you.
What you can do with it
SimpleX has the basic functionality you’d expect:
- Personal conversations (1 on 1)
- Group conversations
- Voice and video calls
- File sharing
- Disappearing messages (configurable per conversation)
- Incognito mode: each new contact sees a different random name
Voice messages, emoji reactions, and read receipts are present. It’s not a minimal app — it works.
Who SimpleX is for
Direct value:
- Journalists and activists protecting sources
- Whistleblowers contacting a newsroom or organisation
- People in countries with aggressive surveillance
- IT professionals reaching clients without sharing a personal number
- Stalking or domestic violence victims communicating without an ex tracing their number
- Lawyers and notaries contacting clients without sharing a personal phone number
- Anyone who wants contact without the other party needing to know their phone number
Less suitable for:
- People who want to find contacts easily (no phone book integration)
- Large groups already on Signal (switching threshold)
- People already satisfied with Signal for their profile
Honest caveats
SimpleX is younger than Signal. The app has existed since 2022 and is still actively developing. The codebase has been audited, but has fewer years of large-scale use behind it than Signal.
The absence of an identifier is also a usability issue: if someone sets up a new device and loses their SimpleX link, the connection is gone. There’s no “forgot password” — there’s no account to recover.
Self-hosting relay servers is possible but requires technical knowledge. For most users, the default SimpleX servers work fine.
SimpleX and Signal side by side
You don’t have to choose. Both apps serve different situations.
Signal is excellent for daily use: fast, widely supported, low barrier. If your contacts already use Signal, that’s the logical choice for most conversations.
SimpleX is the option when it matters that someone never learns your phone number or account ID, and when you want the amount of centrally requestable metadata to be as small as possible.
Next step
Alternatives
- Session guide — no phone number, but with a recoverable identity
- Threema guide — paid, Swiss, no phone number
- Briar guide — P2P via Tor, also works without internet
- Delta Chat guide — encrypted messaging over email
- WhatsApp and privacy: what the lock does and doesn’t protect
Reviews
- Signal and Molly review — Signal with extra privacy options