In plain words
Security.
Only you and the people you talk to can read what you say. Here’s how Murmur keeps it that way, and what it can still see.
Your chat with Nadia Haddad, sealed end to end so only the two of you can read it. Nadia has already checked your security code. She asks for your door code, you send it, and she thanks you. The lock at the top of the chat is gray, so you tap it, then Verify Security Code. You compare the code and tap Mark as Verified. Back in the chat, the lock is green, because you’ve both checked it.
The same chat as it passes through our servers. There is one sealed envelope for each message, and one more when you mark the code as verified, all the same size, with nothing readable on them. Who sent each one is sealed inside, and each one goes to an anonymous mailbox our servers can’t link to you or to Nadia. They see when each one arrives, and the few details listed in How it works, but they have no key to open any of it.
Only you and Nadia hold the keys. Murmur never does. Our servers pass the envelopes along, and that’s it.
Once you’ve both checked your security code, the lock turns green.
The main ideas
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Sealed, end to end.
Your messages, photos and files are sealed on your device, and only the people in the chat can open them. Murmur never holds the keys, so it can’t read them.
Learn more about end-to-end encryption -
No phone number. No email.
Your account is a username and a password, so it isn’t tied to your SIM card or your real name. What we don’t hold can’t leak or be handed over.
Learn more about signing up with a username -
Your profile is sealed too.
Murmur can’t read your name, picture and bio, your contacts, who you block, most of your settings, or the names and pictures of your groups. It never uploads your address book, either.
Learn more about what stays sealed -
Check it’s really them.
Compare your security code once. Tap the lock in your chat, then Verify Security Code. Scan each other’s QR code in person, or compare the numbers another way you trust. When you’ve both marked it as verified, the lock turns green. If the code ever changes, Murmur tells you.
Learn more about security codes -
Your devices, your key.
Use one account on up to 5 devices, and every new one alerts the others. From Settings › Security Center, save your Recovery Key. With it and your password, you’re back in right away on a new phone. We keep no copy, and we’ll never ask for it on a website or in a message.
Learn more about your Recovery Key -
Private by default.
Out of the box, notifications show only the sender’s name, your photo and bio show only to your contacts, a stranger’s request waits in Message Requests, and only the people you chat with see when you’re online. Anyone with your whole username can find you. You can change all of this in Settings, and lock Murmur with a PIN, or the way you unlock your device.
Learn more about Murmur’s defaults and app lock -
What Murmur can see.
Not your messages, photos or files, and not who you talk to. To deliver them, our servers handle a few details, like when a sealed message arrives. We keep as little as we can, and we publish the full list.
Learn more in the full table of what Murmur can see -
Open source and audited.
The code that seals your messages, meaning the encryption, the protocol and the server, is published so anyone can check it. Independent security firms reviewed the design, audited the code and tried to break in. Every report is published.
Learn more about open source and audits
Compared
More private than Signal and Telegram.
Like Signal, Murmur hides from its own servers who sent a message and who is in a group. Unlike Signal and Telegram, it never asks for your phone number.
| Murmur | Signal | Telegram | |
|---|---|---|---|
| One-on-one chats end-to-end encrypted, by default | Yes | Yes | No |
| Group chats end-to-end encrypted | Yes | Yes | No |
| Sign up without a phone number | Yes | No | No |
| The server doesn’t know who sent a message | Yes | Yes | No |
| The server doesn’t know who is in a group | Yes | Yes | No |
Sources, from their own sites. Signal: home page, terms, sealed sender, private groups, phone number at sign-up. Telegram: FAQ, secret chats, privacy policy.
Want to go deeper?
Every detail is in How it works. Each article starts in plain words.
How it works