Decentralized messenger that assigns no identifier to users, not even a random number. Contacts are established via one-time invite links or QR codes, with all data stored on-device only.
Reviewed by Gabriel Bachmann
SimpleX Chat
simplex.chat 4.7 (10)
Messaging Open SourceE2E encryptedNo accountDecentralizedWindowsmacOSLinuxAndroidiOSFree United Kingdom
Rate SimpleX Chat: No account needed
Threat level
Targeted
A targeted-tier tool. Built for a real, capable adversary. Overkill for everyone below. Threat levels
Our take
No other mainstream messenger can honestly say it collects zero metadata about who talks to whom, because every other app still ties you to a phone number, email, or account ID. SimpleX routes messages through relays without linking sender and recipient on the server side, and the protocol has been audited by Trail of Bits. The real trade-off is setup friction: sharing an invite link is awkward compared to searching a username, so getting less tech-savvy contacts onboard takes effort. For high-stakes private communication, that friction is worth it.
GitHub at a glance
simplex-chat/simplex-chat
Stars
18,320
+ 7,054 this week
Last commit
7d ago
healthy
License
AGPL-3.0
Latest release
v6.5.5
22d ago
Stars, last 30d
Website at a glance
simplex.chat
C score 50
Basic website security headers
Graded by Mozilla HTTP Observatory, tested 13d ago
Inspect this site yourself
Measures the security configuration of the tool's own website, not the privacy of the product itself. A strong tool can still score low here.
SimpleX Chat alternatives
Signal Similar look and feel of WhatsApp and other commonly used messaging apps, makes switching easy. Signal requires your phone number as an personal identifier.
Delta Chat Delta Chat doesn't have their own servers but uses the most massive and diverse open messaging system ever: the existing e-mail server network. Chat with anyone if you know…
Brave Talk The person creating the call requires to use Brave Browser, but the participants can join from any browser.
Jitsi Meet Desktop version downloads can be found here .
Stoat Open source, self-hostable Discord alternative, formerly Revolt. Built for communities that want off Discord, but it is not end-to-end encrypted.
iMessage Apple's built-in messenger. End-to-end encrypted between Apple devices.
SimpleX Chat license, in plain English
AGPL-3.0 Strong copyleft · network
Free to use, even commercially. Changes must be published under the same license, and running a modified version as a network service counts as distributing it.
Permits
- Commercial use
- Modification
- Distribution
- Patent use
- Private use
Requires
- Disclose source
- Network use is distribution
- Same license
- State changes
- License and copyright notice
Does not provide
- Liability cover
- Warranty
Why it matters: The network clause is the point. Anyone who runs a modified version as a hosted service has to publish those changes, so the code handling your data stays inspectable. This is why privacy-first projects reach for AGPL.
Plain-language summary of the project's license, not legal advice. Read the full text for the exact terms.