# IO Transfer

> Offline file and text transfer between two devices using fountain-coded animated QR codes — screen to camera, no network path, no account, no pairing, no cloud.

IO Transfer is a progressive web app at https://iotransfer.com/. One device displays an endless QR stream; the other reconstructs the payload with its camera. Bytes travel as light. After the first visit the app works with the network off. Optional matching passphrases encrypt the optical payload (AES-GCM). Every file is SHA-256 verified before save.

## App

- [Home](https://iotransfer.com/): Product overview and entry points for send / receive
- [Send](https://iotransfer.com/send): Encode a file (up to 64 MB) or text snippet as an optical QR stream
- [Receive](https://iotransfer.com/receive): Decode with the device camera; preview and save when complete

## Documentation

- [Quick start](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/quick-start.md): Two-device walkthrough
- [Sending](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/sending.md): Sender settings and tips
- [Receiving](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/receiving.md): Camera and recovery
- [Troubleshooting](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/troubleshooting.md): Dense streams, focus, lenses
- [Install & offline](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/install-and-offline.md): PWA install and HTTPS camera requirements
- [Privacy](https://github.com/cubbysoftware/iotransfer/blob/main/docs/user/privacy.md): No analytics; optical channel is not confidential by default

## Technical

- [Architecture](https://github.com/cubbysoftware/iotransfer/blob/main/docs/technical/architecture.md)
- [Protocol](https://github.com/cubbysoftware/iotransfer/blob/main/docs/technical/protocol.md)
- [Full LLM brief](https://iotransfer.com/llms-full.txt): Single-file product summary for agents

## Optional

- [Sitemap](https://iotransfer.com/sitemap.xml)
- [robots.txt](https://iotransfer.com/robots.txt)
- [Source repository](https://github.com/cubbysoftware/iotransfer)