Experiments

QR Beam

Send a file from one device to another with no internet, no Bluetooth, no USB. The sender's screen cycles through QR codes; the receiver's camera reassembles the file. Everything runs in your browser.

Drop a file here

or click to browse

Type a message (beamed as message.txt) 0 chars · 0 bytes

Chunk size (bytes) Frame rate

8 fps

Passphrase (optional — AES-GCM 256, PBKDF2 250k)

Without a passphrase the transfer is not encrypted — anyone who can see the screen can decode it.

Compress (gzip before chunking — faster for text) Fountain (Luby Transform — missed frames don’t cost a full loop)

Pick a file to begin.

QR sequence will appear here.

Frame 0 / 0 · Loop 0

Hold the receiver's camera up to the screen. The sequence loops automatically until every chunk is captured.

How it works

The sender picks a file. The browser computes its SHA-256, splits the bytes into chunks, and encodes each chunk as a QR code.
The screen cycles through the QR codes at the chosen frame rate, looping forever.
The receiver opens this same page on another device, switches to the Receive tab, and points its camera at the sender's screen.
The receiver decodes every QR it sees, deduplicates by sequence number, and reassembles the file once every chunk has been captured. The SHA-256 is verified before the download is offered.
No server. No internet. The file never leaves your browser.