August 6, 2026
QR codes, but make it chaos
Decimen Optical Transfer: fountain-coded QR file transfer
Your screen can now beam files by flashing QR codes, and commenters are weirdly obsessed
TLDR: A new demo lets one device send files to another by rapidly flashing QR codes at a camera, no internet account or pairing needed. Commenters are impressed, mildly annoyed this wasn’t standard years ago, and already demanding extras like encryption and even sound-based versions.
A scrappy little demo just dropped on Decimen Optical Transfer, and the internet immediately turned it into a "wait, why didn’t we have this already?" moment. The basic trick is gloriously sci-fi for normal people: one device flashes a fast stream of QR codes, another points its camera at the screen, and boom — a photo jumps across with no cable, no account, no app install, and no internet service in the middle. Just light. The creator says the larger experiment hit surprisingly solid speeds, and even this stripped-down version can move a decent-size image in seconds.
But the real sparkle is in the reactions. One commenter basically summed up the collective mood with a digital table-slam: why has file sharing been such a mess for so long if this is possible? That same thread instantly escalated into bonus feature wishlists, with people already fantasizing about secret encrypted transfers and even audio-based versions — because apparently if your phone can "see" a file, maybe it should also be able to hear one. Another commenter skipped the practical talk entirely and just thirst-posted for the math under the hood, declaring the coding method "so lit" like a niche engineering fan club had crashed the party.
The vibe wasn’t angry so much as delightfully incredulous: half impressed, half annoyed that modern gadgets needed a QR-code light show to make offline file sharing feel easy. It’s nerdy, dramatic, a little ridiculous, and exactly the kind of invention that makes commenters act like they’ve discovered a lost future.
Key Points
- •Decimen Optical Transfer demonstrates file transfer between devices by showing animated QR codes on one screen and decoding them with another device's camera.
- •The proof of concept transmits a 512 KB image or an optional 2 MB image, while a larger related experiment reportedly achieved 128 KB/s phone-to-phone with denser encoding methods.
- •The system uses fountain codes with Luby transform coding so the receiver can reconstruct the file from roughly `K·1.15` distinct frames in any order, tolerating dropped frames without needing retransmission.
- •The receiver requires HTTPS because browser camera access via `getUserMedia` is unavailable on insecure origins for non-localhost devices; the demo uses a self-signed certificate through `@vitejs/plugin-basic-ssl`.
- •Implementation details include a self-describing 20-byte frame header, QR decoding via `zxing-cpp` compiled to WebAssembly due to Safari's lack of `BarcodeDetector`, and deterministic math to avoid cross-engine desynchronization.