QR Send blog
How optical file transfer works, what the QRTP protocol does under the hood, and when a stream of QR codes is the right way to move a file.
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Comparisons QR Send vs WeTransfer and cloud sharing
Cloud sharing is fast and asynchronous, and leaves a copy on someone else's disk. QR Send keeps the file between the two devices in the room.
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Engineering Fountain codes in a stream of QR codes
Why QRTP uses Wirehair instead of retransmission, and what that buys when frames are blurred, dropped or read out of order.
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Definitions How a stream of QR codes carries a whole file
A QR code holds at most a few kilobytes. Here is how thousands of them carry an arbitrary file, and why lost frames do not matter.
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Guides How to transfer files to and from air-gapped machines
Step-by-step: move a file into or out of a machine that has no network, using a camera and a stream of QR codes.
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Use cases One screen, many receivers: QR Send in an office
Leave a QR stream running on a screen and let anyone in the room pull the file over WiFi or optically, whenever they arrive.
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Security Optical vs radio file transfer: the attack surface
Radio links radiate in all directions and are observable at a distance. An optical link sends bytes only where the camera can see.
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Guides Password-protected transfers with Safe Send
Safe Send encrypts a file before a single QR frame is drawn, so the optical stream carries ciphertext rather than your document.
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Guides QR Send CLI guide for power users
The qrsend binary renders QR streams straight in your terminal, with flags for frame rate, grid size, error correction, colours and auditing.
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Comparisons QR Send vs AirDrop
AirDrop is excellent inside Apple's ecosystem. QR Send transfers across whatever two devices are in the room, with no shared network.
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Guides Streaming live audio and video over QR codes
QR Send can beam a camera, a microphone, or a media file as a live stream, and the receiver plays it as it arrives.
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Definitions What is QR Send?
QR Send moves files and live media between devices by streaming fountain-coded QR codes, so the transfer works with no network at all.
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Definitions What is the QRTP protocol?
QRTP is the QR Transport Protocol: a framing format plus fountain coding that turns a one-way camera link into reliable file transfer.