Similar look and feel of WhatsApp and other commonly used messaging apps, makes switching easy. Signal requires your phone number as an personal identifier.
Official website signal.org
Our take
The phone number requirement is the real friction, and there is no getting around it without a burner. Accept that and Signal is the easiest secure messenger to actually get your non-technical friends onto, which matters more than any feature, because the most private app is useless if nobody you know will install it. The desktop apps are good and the protocol is the one everyone else copies.
GitHub at a glance
signalapp/Signal-Android
Stars
28,947
+ 55 this week
Last commit
2d ago
healthy
License
AGPL-3.0
Latest release
v8.15.3
4d ago
Stars, last 10d
Listed in
Signal alternatives
SimpleX Chat 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.
Session No phone number or email address is required to signup. Similar functionality like Element, but still in an earlier stage of development. Decentralized servers routed through…
Status No phone number or email address is required to signup. Uses the peer-to-peer (p2p) messaging protocol Waku that removes centralized third parties from messages.
Threema No native desktop apps available yet, but there is a web version for your browser. No phone number is required to signup but there is a payment involved to get the app.…
Molly Hardened fork of Signal for Android that adds an encrypted local database, automatic RAM wiping on lock, and Tor/SOCKS proxy support via Orbot. Ships in two variants: one with FCM push and one fully FOSS without Google.
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…
Signal 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.