Overview
High-speed 1D/2D QR scanner and air-gapped optical file transfer utility connecting PC and mobile via screen-to-camera streams.
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Productivity / Tools
QR Scan4u
QR Scan4u is a high-performance productivity utility combining an ultra-fast 0.1s QR and barcode scanner with an air-gapped optical file transfer system (QFT Protocol). Beyond instant code recognition, product lookups, and anti-phishing link verification, QR Scan4u enables direct peer-to-peer file and folder transmission between Windows PCs and mobile devices (iOS/Android) purely through screen-to-camera animated QR streams—requiring zero Wi-Fi, Bluetooth, cellular data, or server mediation.
Scans, generates, and transfers data through camera-first, network-independent workflows.
Platforms
AndroidiPhoneWindows
Tech stack
FlutterDartQFT Optical ProtocolAir-Gapped TransferCamera Stream ProcessingIsar Database
Product purpose
Provide an all-in-one scanning, generation, and air-gapped optical file transfer utility that guarantees absolute privacy, lightning-fast workflows, and zero-network cross-device sharing.
Target user
Professionals, field technicians, and privacy-conscious users who need dependable industrial-grade scanning alongside secure, air-gapped file movement between desktop PCs and mobile devices.
Role and ownership
Product planning, UI implementation, architecture decisions, and app delivery.
Release Notes
v1.0.8v1.0.82026-09-06
- - Ultra-fast real-time scanning for QR codes and 1D/2D barcodes
- - Offline optical peer-to-peer file transfer (QFT1 protocol) between screens and cameras
- - Safe PC-to-Mobile file transmission without Wi-Fi or internet connection
- - Updated 2026 store-compliant Privacy Policy and comprehensive legal terms
Main features
- - Screen-to-Camera Optical File Transfer: Stream and assemble multi-file batches without internet, Bluetooth, or cables
- - Automatic Chunk Assembly & Missing Block Compensation for reliable 100% data integrity
- - Sub-100ms camera recognition with one-touch torch, precision zoom (2x-5x), and instant lens reset recovery
- - Smart 1D Barcode product lookup with integrated manufacturer specs and web search
- - Proactive URL Phishing Shield inspecting target domains before opening in browsers
- - Custom QR generator supporting Wi-Fi configurations, vCards, URLs, SMS, and clipboard payloads
- - Detailed scan inspect modal with user notes, bookmarking, and one-tap PDF report export
- - Continuous batch scan mode optimized for logistics, warehousing, and inventory audits
- - Searchable local history indexed by category, timestamp, and favorite tags
Technical notes
- - Built with Flutter & Dart for unified cross-platform performance across Windows, iOS, and Android
- - Proprietary QFT (Quick File Transfer) optical streaming protocol with dynamic byte chunking and CRC32 verification
- - Real-time camera frame analysis pipeline with hardware-accelerated decoding and focus management
- - Ultra-fast embedded Isar database for zero-latency local history querying and state persistence
- - Windows distribution engineered with Inno Setup for smooth installer and portable zip deployment
Future improvements
- - Bidirectional optical camera-to-screen feedback channel for dynamic baud-rate optimization
- - Direct desktop-to-desktop webcam file streaming
- - Hardware barcode scanner HID keyboard wedge integration on Windows
Store screenshot
0.1s Real-time Live Scanner
Store screenshot
Optical Offline File Receiver
Store screenshot
Offline QR File Sender (Mobile)
Store screenshot
Windows Desktop File Sender
Store screenshot
Smart Product & Barcode Lookup
Store screenshot
Anti-Phishing Link Shield
Store screenshot
All-in-One Multi-format QR Creator
Store screenshot
Result Detail, Memo & PDF Export
Store screenshot
Fast Search & Favorite History
Store screenshot
Structured History by Category
Store screenshot
Tailored Continuous Scan Settings