A new era of file sharing: QR codes as a bridge between smartphones

Modern technology continues to impress with its ingenuity, offering unexpected solutions to everyday tasks. In an era when wireless protocols such as Bluetooth and Wi-Fi Direct have become standard for data transfer between mobile devices, innovative approaches are emerging that challenge familiar assumptions. One such breakthrough is the development of an experimental browser-based platform that allows smartphones to exchange data using only QR codes. This approach, created by an independent programmer under the pseudonym bashalarmistalt, opens new horizons for users who need a simple and accessible way to share information.

Decimen Optical Transfer: how does it work?

At the heart of this innovative system is a technology called Decimen Optical Transfer: fountain-coded QR file transfer. Its operating principle is strikingly simple and effective. Instead of relying on complex network protocols or installing additional apps, the platform uses the smartphone’s built-in camera and screen. Information is broken into small fragments, each encoded as a QR code. These QR codes are then rapidly changed on the screen of the sending device, at up to 60 frames per second. Another smartphone, pointing its camera at the first device’s screen, sequentially reads these dynamic QR codes. The algorithm running on the receiving device gathers the received fragments and reconstructs the original file.

A feature of this system is the use of “fountain codes”—a special type of encoding that ensures reliable data transfer even when individual packets are lost or duplicated. Each QR code contains a service header that includes a session identifier, sequence number, the number and size of data blocks, as well as the total file length and its hash. This allows the receiving device to determine exactly which part of the information was received and place it correctly.

Speed and potential: challenges and opportunities

The developer claims that data transfer speed using Decimen Optical Transfer can reach an impressive 190 KB/s. While this may seem modest compared with modern high-speed transfer methods, it is a significant achievement for a technology that requires nothing more than two smartphones with cameras and internet access to load the web app. In demonstration tests conducted on an iPhone using the Apple ProMotion camera, speeds of around 128 KB/s were achieved in handheld mode. The stated maximum speed of 186 KB/s was recorded under ideal conditions, when both devices were stationary.

This development, released under the MIT license, opens the door to new use cases. Imagine needing to quickly transfer a small document, contact information, or a website link when Bluetooth is turned off, the Wi‑Fi signal is weak, or you do not want to grant an app extra permissions. In such cases, Decimen Optical Transfer becomes an extremely convenient tool. It removes the need to install special software, search for shared networks, or grant access to sensitive information such as contacts, files, or location data.

Historical context and future prospects

The idea of transmitting data using visual signals is not new. Even at the beginning of telegraphy and telephony, light signals were used to transmit information. However, with the emergence of radio waves and network technologies, visual methods moved into the background. Bashalarmistalt’s development shows that even today, when digital interaction has reached incredible heights, there are still opportunities to return to simple yet effective solutions adapted to modern devices.

Using Claude Code to create a cached web app that runs directly in the browser is also a significant achievement. This makes the platform accessible to virtually any modern smartphone, regardless of operating system, as long as it has a browser and a camera. The developer emphasizes that although similar concepts have been implemented before, his approach, based on Claude Code, was developed independently, demonstrating an active search for new directions in mobile technology.

Although Decimen Optical Transfer is unlikely to become the primary tool for transferring large files due to speed limitations, its potential for quick and convenient sharing of small pieces of information is undeniable. This development may find use in environments with limited network availability, in situations where security and privacy are the priority, or simply as an interesting alternative to familiar methods. It reminds us that innovation often lies in the simplest and most accessible solutions, and that the future of mobile technology may be more diverse than we tend to imagine.