Signal
The end-to-end encrypted messenger that everything else quietly copies.
TL;DR verdict
If the question is how a private conversation should work by default, Signal is still the reference implementation. The phone-number requirement is the one persistent scratch, and the recent usernames feature files it down without removing it.
What we like
- Best-in-class E2E for messaging, with a protocol the rest of the industry has copied
- Usernames now let you hand out a handle instead of your phone number
- Nonprofit governance and a published protocol audit history
- Sealed sender and private contact discovery reduce server-side metadata
Where it falls short
- Requires phone number by default to register an account
- Desktop client is still an Electron app with the usual memory footprint
- Backup and device migration story on iOS remains fussier than iMessage
- No first-class business or team features, which is fine but worth naming
TL;DR verdict
Signal is the messenger to install first and argue about later. The encryption is the standard the rest of the industry is measured against, the app stays out of the way, and the nonprofit funding model means nobody inside the company is being paid to make your inbox worse. Set a username, turn on disappearing messages, move on.
What it does well
The Signal Protocol is the thing. Every message and call is end-to-end encrypted between devices, with forward secrecy and post-compromise security baked in at a level that WhatsApp, iMessage and Messenger have all borrowed from over the last decade. The client-side code is open, the server code is open, and the audits are not marketing summaries.
Around the crypto, the product decisions have been consistently sober. Sealed sender hides who is talking to whom from Signal's own servers. Private contact discovery keeps your address book off the network in cleartext. Disappearing messages, view-once media, and the ability to relay calls through Signal's servers to hide your IP from the other party are all one toggle away.
Usernames are the meaningful 2024 addition finally settled in. You can publish a handle, keep your number private, and hand the handle to a source or a stranger without exposing anything downstream. This closes the single most cited complaint about the product without breaking the anti-spam model.
Where it strains
The phone number is still the account, underneath everything. If SIM-swap risk is inside your threat model, Signal wants a strategy — a dedicated number, a data-only eSIM, a burner. Usernames help, they do not eliminate.
The desktop app is functional and a little heavy. Message history migration between phones on iOS still involves more taps than it should. Neither is a reason to avoid Signal; both are reasons the answer to "which client" is not always "just Signal".
Group calls scale, but not as smoothly as a dedicated tool at the fifty-person mark. For the conversations Signal is actually meant to protect, that ceiling does not matter.
Who it's for
Anyone who wants a private conversation with another person to actually be private, with no configuration and no subscription. Journalists talking to sources, activists coordinating in places where the coordination is the story, travellers who want a client that behaves on unfriendly networks. If the other person is also willing to install it, Signal is the default answer.
Frequently asked
Do I still have to give Signal my phone number?
To register, yes. Once the account exists, you can set a username and turn off phone-number discoverability so that people who want to message you only need the handle. The number stays on file with Signal for anti-spam and account recovery, but it no longer needs to be the thing you hand to a source.
Is Signal really more private than WhatsApp if both use the Signal Protocol?
The message content protection is comparable. The difference is the metadata surface around it. Signal runs on donations rather than ad targeting, publishes its server code, and collects strikingly little on the sides of a conversation. WhatsApp sits inside Meta and shares more with the parent than most users assume.
Can I use Signal without a smartphone?
The desktop app has to be linked from a phone, and a phone number is still required at registration, so a fully phoneless setup is not supported. A cheap secondary handset with a fresh number is the usual workaround for people who want to keep Signal off their main SIM.