https://codeberg.org/blast/blastqr
Hello! I’ve been working on blastQR for a couple of years now and I thought this community might find it useful. Feel free to try it and ask me anything!
blastQR is a fully open-source file transfer app and protocol that works completely offline. You can even use it in airplane mode. Data is transferred through sequences of QR codes displayed on a sender device and scanned by a receiver device’s camera. It uses RaptorQ codes so the receiver can recover the file from any sufficiently large subset of frames.
Note that although I have made use of AI as a coding assistant I do not consider this to be a vibe-coded app and I do plan to continue improving it and supporting it in the future.
See video of blastQR in action: https://github.com/user-attachments/assets/038a2567-70c8-47c8-b165-dea858d1aef3
Here are some of the key features:
- Works fully offline: No internet, Wi-Fi, Bluetooth or servers. Your data stays offline.
- One-to-many distribution: Share the same file with multiple devices simultaneously using a single blastQR broadcast.
- Cross-platform: Android, iOS, macOS, Linux and Windows, plus a command-line tool that can send from a terminal, even over SSH.
- Password encryption: You can optionally encrypt files with an auto-generated password or a custom one.
- Media compression: The app supports lossy image compression and video transcoding for quicker transfers.
- Multiple codes on screen: Shows multiple QR codes at once for higher speed. With 8 codes at 60 fps, transfers peak at around 1.4 MB/s.
- Send multiple files in one go: They’re zipped into one transfer and unpacked into separate files on the receiver.
- Sound feedback: The receiver plays a short tone when it has the whole file, and the sender stops automatically when it hears it.
- Start scanning at any point: No need to catch every code, just keep the camera on the screen until it’s done. Blurry or missed codes don’t matter.
- Regular QR scanner: You can also scan normal QR codes and save them.
- Open protocol that other apps can implement
- Built-in file manager
I’m trying to build a small community around the project so it can be improved and maintained and so it can reach more people in the future.
Downloads for all platforms can be found here: https://codeberg.org/blast/blastqr/releases/latest
Wouldn’t any security camera potentially be able to steal the information by inputting the QR codes though? It’s not truly airgapped when someone can view or also be able to see the information that’s being sent.
Yes, absolutely! anyone who can capture the QR codes could reconstruct the data. That’s why blastQR also lets you password encrypt any transfer. It depends on your usecase. You might not care if you’re already intentionally publicly broadcasting to multiple devices.
Air-gapping refers to network isolation not necessarily confidentiality. It means you can transfer data to and from devices that are completely disconnected from any network.
Which also includes the information not being seeing or taking, it’s kinda one of the main points. Your program is not even remotely similar to being airgapped and you shouldn’t be saying or even implying that feature. Especially in a comm like this. Why would you want to transfer without being connected to a network or a “physical” connection? For privacy and security, and lots of airgapped system still utilize networks and lines.
If you don’t trust the network stack to be secure. This use case definitely counts as airgapped imo. Even in airgapped environments people use usb to transfer data. But USB also has huge security issues like BadUSB. So this app shifts the attack surface to the camera and the app. Not necessarily more secure but still an option I haven’t seen explored much.
As explained in the readme you should enable password encryption when transferring sensitive data. I’m not claiming the program itself is air-gapped, just that transferring files between air-gapped systems is a legitimate use case.