QRelay ⚡

Drag. Drop. Scan. Done.

QRelay is a lightweight, zero-login file transfer platform that enables instant file sharing between devices using QR codes and temporary download links. Designed for speed, privacy, and simplicity, it removes the friction of traditional file-sharing methods by requiring no accounts, installations, or pairing.

🌐 Live Demo: https://qrelay.netlify.app/

Overview

Moving files between devices should take seconds—not minutes.

Whether you're working on a college lab computer, borrowing a friend's laptop, or transferring a document to your phone, most existing solutions require unnecessary steps such as signing in, installing applications, or configuring connections.

QRelay provides a frictionless alternative:

Upload a file.
Receive a QR code and a unique 6-digit access code.
Scan the QR code or enter the code on another device.
Download the file instantly.
The file is automatically deleted after 10 minutes.

No accounts. No installations. No permanent storage.

Problem Statement

Existing file-sharing solutions often involve:

User authentication
Application installation
Bluetooth pairing
Emailing files to yourself
Permanent cloud storage for temporary transfers

These workflows are slow and inconvenient, especially when transferring small files between nearby devices.

QRelay solves this by offering secure, temporary file sharing directly through the browser.

Key Features

QR code based file sharing
Alternative 6-digit access code
No login or registration
Browser-based access across devices
Automatic file deletion after 10 minutes
Secure Azure Blob Storage
Supports uploads up to 10 MB
Database-free architecture using in-memory sessions

How It Works

User uploads one or more files.
Backend uploads files to Azure Blob Storage.
A unique session and 6-digit access code are generated.
A QR code pointing to the download page is returned.
The recipient scans the QR code or enters the access code.
Files stream directly from Azure Blob Storage.
After 10 minutes, all files are automatically deleted.

The entire workflow is designed around temporary sharing. No user data or files remain after expiration.

Why No Database?

QRelay is intentionally designed as an ephemeral platform.

Since every uploaded file expires after 10 minutes, persistent storage would introduce unnecessary complexity without improving the user experience.

Instead, session metadata is maintained in memory while files reside temporarily in Azure Blob Storage.

Technical Highlights

Designed a stateless architecture using Azure Blob Storage and in-memory session management.
Implemented automatic file expiration and cleanup after 10 minutes to improve privacy and minimize storage usage.
Generated QR codes and unique 6-digit access codes for seamless cross-device file sharing.
Built a responsive React frontend with a Node.js and Express backend.
Dockerized the application for consistent deployment across environments.

Conclusion

QRelay demonstrates how a simple idea can solve a common everyday problem through thoughtful system design. By combining cloud storage, temporary sessions, QR-based sharing, and automatic cleanup, the platform provides a fast, secure, and frictionless way to transfer files across devices without requiring user accounts or permanent storage.