Messages nobody
else can read.

Your messages are encrypted on your device before they are sent. We carry them and cannot read them.

Maya Chen

End to end encrypted

Messages in this chat are encrypted
landed, heading to yours09:08
perfect, door code is 441709:09
do you need me to bring anything09:10
just yourself, there is food here09:11
also, the flight lands at 6:40, terminal 209:12
noted, i will be there09:12
see you in a bit09:13
Message

Our servers only hold the encrypted version.

A message is encrypted on your device and decrypted on theirs. In between, we store the encrypted version. We hold no key that opens it.

What you wrote

the flight lands at 6:40, terminal 2

What we store

8f2a41c7d9e0b35a6114fc820d7e93a15c4b6802ff31d95e7a08c264b19d3f7e

There is no readable copy.

Search

terminal
AllTextLinksMediaVoice

Maya Chen

the flight lands at 6:40, terminal 2

2h

Devon Park

here is the lease pdf

1d

Lia Moreno

shared a link

3d

Searched on this device.

Search across every chat.

Words, links, files and voice notes. The index is built on the device that can already read your messages, so nothing is uploaded to search it. If this device has no key for a message, the app counts those messages in the results.

Encrypted by default

Every message is encrypted on your device before it is sent. It applies to every chat and cannot be turned off.

Search on the device

Search every word, link and file you have been sent. The index is built on your device and your query never leaves it.

Nothing to install

It runs in a browser and adds to your home screen. It uses the Surf account you already have.

Check who you are talking to.

Every chat carries a number derived from both sides' keys. Read it out together, and if it matches, no third party is in the middle. If someone's keys change, the app says which device changed and how.

Read the protocol

Safety number

410932771460582319467720518863502419387612604481593772065038

Read it aloud together. If both sides match, nothing is in the middle.

What encryption does not cover.

Three limits on the claim above.

Groups over 256 people
The group scheme covers 256 members. A larger group is not end to end encrypted, and the app says so in the group itself.
Messages sent before we shipped it
A small number of early messages predate encryption and were stored readable. Everything sent since is encrypted.
The person you are writing to
Encryption protects a message in transit and at rest. It cannot stop someone in the conversation from taking a screenshot.

Paid for by donations.

Donations pay for the servers that carry encrypted messages, and for the relay that carries a call when a direct connection will not form. There is no advertising and no tracking.

Donate
What it costs
Nothing
Advertising
None, on any account
Tracking
None
What we store
Encrypted messages and delivery routing