WhatsAppUmbera
Phone number to sign upWhatsAppRequired. Usernames can be reserved, and WhatsApp says a phone number is still needed to register and use the app.UmberaNot required. A username and password; no email either.
End-to-end encryption, one-to-one chatsWhatsAppYes, by default. Personal messages and calls, with no settings to turn on. Chats with businesses that use certain Meta services are not considered end-to-end encrypted.UmberaYes, by default. Every chat; there is no unencrypted chat type.
End-to-end encryption, groupsWhatsAppYes, by default. Group chats included, since April 2016.UmberaYes, by default. Groups use MLS (RFC 9420). The server doesn’t know a message is for a group or who is in it.
Post-quantum protectionWhatsAppNot documented. Not mentioned in the official pages we checked.UmberaMessages: yes. Calls: no. Every message envelope is sealed with X25519 and ML-KEM-1024 together. Calls use DTLS-SRTP (WebRTC), which is not post-quantum.
Sender and metadataWhatsAppNot documented. Not described in the official pages we checked.UmberaSender sealed inside the ciphertext. Messages go to a mailbox address only the two people can derive, and it changes periodically. Sizes are padded to blocks. The server sees the delivery time.
Open sourceWhatsAppNo. The Terms of Service forbid decompiling or extracting code. End-to-end encryption uses the open-source Signal Protocol.UmberaCryptographic core only. umbera-core (Rust) is open source under Apache-2.0 on GitHub and crates.io. The app and the server code are not published.
Built-in TorWhatsAppNot documented.UmberaYes. One switch routes all app traffic through Tor.
Channels and communitiesWhatsAppYes, Channels. Channels are not end-to-end encrypted by default.UmberaYes, Communities. Channels with a separate pseudonym in every channel; private channels are end-to-end encrypted. Open during the trial, then part of Umbera Premium.
Disappearing messagesWhatsAppYes. 24 hours, 7 days or 90 days, with a default timer for new chats; groups have their own setting.UmberaIn one-to-one chats. 1 minute, 1 hour, 1 day or 1 week; deleted on both phones, attached files deleted from the server. Not available in groups yet.
PriceWhatsAppFree. WhatsApp notes that data charges may apply.UmberaFree plan and a subscription. After a free trial, a few contacts stay free for good. Encryption, Tor and Shield are always free. Umbera Premium adds any number of people, groups and Communities.