Optical File Transfer
Send a file between two devices using only a screen and a camera — no Wi-Fi, Bluetooth, or cable.
The Optical File Transfer is a completely free online tool that requires no sign-up or account. Send a file between two devices using only a screen and a camera — no Wi-Fi, Bluetooth, or cable. Instant results in your browser — no downloads, no limits.
📁 Choose a File
Drag & drop a file here
or click to browse · any file type
Nothing is uploaded — the file never leaves this device
⚙️ Stream Settings
Faster is quicker but harder for the camera to keep up. Drop it if the receiver stalls.
📷 Scan the Stream
Point this device's camera at the broadcasting screen and hold it steady so the QR code fills the guide box. Decoding happens entirely on this device.
Frequently Asked Questions
How does sending a file over QR codes actually work?
The file is split into small blocks and broadcast as an endless stream of animated QR codes. Each frame carries a random XOR mix of blocks rather than one fixed piece, so the receiving camera can miss frames, join late, or lose focus and still rebuild the file from whatever it does catch. This is called fountain coding.
Do I need internet, Wi-Fi, or Bluetooth?
No. Once the page is loaded, everything runs offline in the browser. The file is never uploaded anywhere — the only thing travelling between the two devices is light from one screen into the other camera.
How fast is it?
Expect roughly 3-12 KB per second depending on the QR density and frame rate you pick, and how steady the camera is. It is best suited to small files: a document, a photo, a config file, or an audio clip rather than a video.
How do I know the file arrived intact?
The sender includes a CRC-32 checksum of the original file. After the receiver rebuilds every block it recomputes that checksum and tells you whether it matches, so you know the copy is byte-for-byte identical.
Why is my transfer slow or stalling?
Usually the camera cannot keep up with the frame rate, or the QR is too dense to resolve. Lower the frame rate, choose a smaller QR density, increase the error correction level, fill the guide box with the code, and make sure the sending screen is bright and free of glare.
Is there a file size limit?
There is no hard cap, but the format allows 65,535 blocks, and the practical limit is your patience. Files under a few megabytes are realistic; anything larger will take a long time. The tool shows an estimated transfer time before you start.
Which browsers and devices work?
Any modern browser with camera access over HTTPS, including Chrome, Safari, Edge, and Firefox on both phones and desktops. The device sending only needs a screen; the device receiving only needs a camera.