AirGapQR is a premium, web-based tool for high-capacity, fully offline file/text transfers between devices. By unifying Fountain (LT-Codes) and Sequential algorithms into a single high-performance SPA, it provides the most robust and responsive cross-device transmission experience possible over pure visual light.

https://evcli.github.io/AirGapQR/

• SPA Dual-Engine Architecture: Seamlessly hot-swap between Fountain Mode (Drop-loss resilient) and Classic Mode (Sequential simplicity) without reloading.
• Infinite File Streams: Powered by the Fountain internal engine, handle large files with zero frame-loss anxiety.
• Smart UX Feedback:
  • Grid-Collapse: In the receiver, completed rows automatically hide to reduce visual clutter.
  • Row-Indexing: Precise 1-referenced row labels (1, 21, 41...) for tracking progress.
  • Defensive Preparation: Enter key intelligence only triggers re-calculation when data (size/file/text) actually changes.
• Full Privacy: 100% Client-side processing. No server-side storage, no tracking, just local Gzip compression and QR block-gen.

AirGapQR supports URL parameters for quick workflows, allowing you to create bookmarks or standard links:

• ?mode=text: Directly opens the Sender in Text Mode and automatically focuses the text area so you can immediately Ctrl+V to paste.
• ?text=YOUR_MESSAGE: Automatically switches to Text Mode and pre-fills the input box with the provided message.
• ?mode=file: Directly opens the Sender in File Mode. Note: Unlike the F keyboard shortcut, accessing via URL parameter will not automatically open the system file picker on page load. You will need to manually click the drop zone to select a file.

AirGapQR is designed for power users who prefer the keyboard.

• S / R : Switch Tab (Sender / Receiver)
• F / T : Switch Mode (File Mode / Text Mode) - Automatically triggers file dialog or text focus.
• Enter : Prepare Beam. Triggers metadata generation and enters the "Manifest View". Only active when configuration changes to prevent accidental restarts.
• Space : Play / Pause. Toggle active QR transmission.
• Escape : Reset Everything. Clears file state, UI, and memory for a fresh session.
• Cmd + R : (Mac Only) Fully compatible. Modifiers are respected so you can refresh the page normally.

• index.html: The unified UI entry point and state manager.
• lib/engine-fountain.js: Core implementation of LT-Codes and PRNG.
• lib/engine-sequential.js: Classic buffer-slice-index logic.
• lib/: Offline dependencies (Tailwind, Pako, Html5Qrcode, QRious).

• SPEED (FPS): Real-time sensitive. Adjusting the slider or typing a new value applies instantly during live transmission.
• QR SIZE (Density): Structural. Adjusting this requires a Manual Re-Prepare (Press Enter or Prepare) to re-calculate the segments.

Created with focus on privacy and pixel-perfect UX.