We can't read your clipboard.
We built it that way.
Linkup has no server in the sync path. Your clips move directly between devices you approved, sealed with keys that only those devices hold. Here is exactly how that works and what little we ever see.
The short version
Linkup syncs your clipboard peer to peer. There is no Linkup cloud that stores, reads or forwards your clips, and you don't need an account to use it.
What we never get
- Your clipboard contents
- Your clipboard history
- Your encryption or pairing keys
- Your contacts, files or photos
- An account, email or phone number for free use
What can exist, and where
- Clip history, encrypted, on your own devices
- Your device names, on your linked devices
- An email and license key, only if you buy Pro
- Standard web server logs for this website
How your clips travel
When you copy something, Linkup encrypts it on that device first. It then finds your other devices over a public peer-to-peer network (the Hyperswarm DHT) using a topic only your devices know, and sends the sealed clip straight to them over an encrypted connection.
Some public peers help your devices find each other and punch through home routers. They see that two devices are talking, the way any internet router does, but they only ever handle ciphertext they cannot open.
Encryption
Every clip is encrypted on the device where you copied it, before it leaves. We use well-studied, open primitives from libsodium.
- Clip encryption
- XChaCha20-Poly1305 (authenticated)
- Key derivation
- Argon2id
- Transport
- Noise protocol streams over Hyperswarm
- Storage format
- Append-only Hypercore logs, merged with Autobase
- Images and files
- Encrypted chunks in Hyperdrive
- Who holds keys
- Only devices you approved
Pairing and devices
Your devices link by scanning a QR code or entering an invite code. Having the code is not enough to join.
You approve every device
When a new device asks to link, your existing device shows its name and a short code. Nothing syncs until you tap Approve.
See and remove devices
The Devices screen lists everything linked. Remove a device and it stops receiving new clips.
Safe links only
Pairing links that open the app are checked before anything happens, so a malicious link can't silently pair you.
Sensitive clips stay home
When your password manager marks a copy as sensitive, Linkup keeps it on that computer and never sends it to your phone.
On your devices
Your clip history lives in Linkup's own app storage on each device. On Android, pairing keys are sealed in the Android Keystore, and Linkup's data is excluded from cloud backups so your keys never end up in someone else's backup.
You choose how long history is kept. Deleting a clip or clearing history removes it from that device, and removing a device stops it from receiving anything new.
The Linkup apps include no ads, no analytics SDKs and no trackers.
Payments and Pro
Free Linkup needs nothing from you. If you buy Pro, payment is handled by our payment provider (Google Play on Android, Lemon Squeezy on desktop). We receive your email and a license record so we can deliver and restore your license. We never see your full card details.
Pro's optional relay stores encrypted copies of your clips so they can reach a device that was offline. The relay has no keys and cannot read them.
Your choices
Because your clips never reach us, the fastest way to delete them is in the app: clear history, remove a device, or uninstall. For anything tied to a Pro purchase, such as your email or license, email privacy@linkup.app and we'll export or delete it within 30 days.
Report a vulnerability
Found a security issue? Please email security@linkup.app before going public. We'll confirm receipt within 3 working days and keep you posted until it's fixed.