How sync works

Alerse syncs your browser between your devices through a server that stores only data it cannot read. This page says what syncs, how the encryption works and what to do when a device is lost.

Your laptophas the keys

encrypted

Sync serversees only ciphertext

encrypted

Your other devicehas the keys

What syncs

Bookmarks, open tabs, Spaces, passwords, history and settings. Each Space syncs on its own, so a work Space stays apart from a personal one. The Sync page lists every Space with its tabs on this device and on each of the others.

How the encryption works

When you create an account, Alerse makes 24 words. They hold the account's secret key and never leave your devices. With your password they derive the keys that encrypt everything before it is sent.

A new device needs both the 24 words and the password; neither alone opens the account.
The server cannot reset either. Keep the words on paper or in a password manager, apart from the password.
Each device signs its requests with a key of its own.

Your own server, or the Alerse server

A server of your own is the better choice: your data stays with you. Use the alerse-sync image with Postgres, in Docker or Kubernetes; the guide is in the alerse-sync repository.

docker run -e DATABASE_URL=postgres://… -p 8295:8295 ghcr.io/vizzletf/alerse-sync:0.2.1

If you would rather not run one, pick the Alerse server at sync.alerse.app. Its operator offers it voluntarily and free, without any guarantee, and takes no responsibility for the data on it; it may stop, and it holds a few accounts for now. Terms · Privacy

If you lose a device

Open Sync on another device, choose Devices and remove the lost one with your password. It stops getting anything new from its next request on. Its own copy of the data stays on it, so lock or wipe it as well.

Limits

Devices send only what changed, in batches: open tabs about 15 seconds after a change, everything else about a minute after. A device with nothing new sends nothing but an hourly check.

The server enforces its own limits per device and per Space, whatever a client sends.
An address that keeps sending refused requests is shut out for 15 minutes.