Duet — Offline File Transfer

Duet sends what matters from one phone to another — and gets out of your way.

Pick a file, a contact, a Wi-Fi password, a 2FA setup code, or any text. The
sender shows a QR code; the receiver scans it. For larger files, the two phones
connect directly over your local network. Everything is end-to-end encrypted,
and nothing ever touches a server.

No account. No sign-up. No ads. No tracking. No cloud.

WHY DUET
• Reliable by design — built to finish the transfer, every time.
• Truly private — your data goes phone-to-phone, never through us. We can't see
it because it never reaches us.
• Zero clutter — no ads, no upsells, no “create an account” wall.

WHAT YOU CAN SEND
• Files of any kind — documents, photos, videos, archives. Streamed directly,
so size isn't a problem.
• Wi-Fi credentials — share your network without reading the password aloud.
• Contacts — send a contact card that drops straight into the other phone.
• 2FA / authenticator setup codes — move your TOTP seeds to a new phone.
• Plain text and links.

HOW IT WORKS
• Small items travel in a single QR code — scan and done, no network needed.
• Larger items use animated QR or a direct local-network link between the two
phones. Your data stays on your local network; it never goes to the cloud.
• Every transfer is encrypted end-to-end. For the local-network mode, both
phones show a quick visual match-check first, so you know there's no one in
the middle.

PRIVACY YOU CAN VERIFY
• Data Not Collected. No analytics SDKs, no ad SDKs, no trackers.
• No internet connection is used to move your data.
• Transfer contents are never written to permanent storage.

Duet is free, and it stays free. No subscriptions, no “pro” paywall on the core
transfer.