QR Code Generator

A self-hosted batch QR code generator built with Flask. Paste URLs or upload a .txt file to generate multiple QR codes at once, then download them individually or as a ZIP.

Features

• Batch generation — generate up to 20 QR codes at once
• PNG & SVG output — raster or vector format
• Custom colors — pick any foreground/background color
• Error correction — four levels (L / M / Q / H)
• Adjustable size — 100–2000px for PNG output
• File upload — drag-and-drop a .txt file of URLs
• ZIP download — download all generated codes in one click
• Dark / Light theme — toggles automatically based on system preference
• Server-side validation — file type, size, and content checks

Quick Start

git clone https://github.com/nextframedev/qr-code-generator.git
cd qr-code-generator
bash start.sh

The app will:

1. Create a Python virtual environment
2. Install dependencies
3. Start the server at http://localhost:5050

Manual Setup

python3 -m venv venv
source venv/bin/activate
pip install -r requirements.txt
python3 app.py

Usage

1. Open http://localhost:5050 in your browser
2. Enter URLs — paste one URL per line, or upload a .txt file
3. Configure options (optional):
   • Format — PNG (raster) or SVG (vector)
   • Error correction — L (7%), M (15%), Q (25%), H (30%)
   • Size — pixel dimensions for PNG (ignored for SVG)
   • Colors — foreground and background hex colors
4. Click Generate QR Codes
5. Download individually or as a ZIP archive

URL File Format

Plain text, one URL per line. Lines starting with # are treated as comments.

# Example links
https://quietlinepress.com
https://nextframe.dev
https://opennote.dev
https://opennotes.dev

Configuration

Setting	Default	Range / Options
Port	5050	Set in app.py
Debug mode	true	FLASK_DEBUG env var
Secret key	qr-dev-secret	SECRET_KEY env var
Max URLs per batch	20	—
PNG size	300px	100–2000px
Error correction	M	L / M / Q / H
Max upload file size	1 MB	—

Project Structure

├── app.py              # Flask application
├── start.sh            # Startup script (venv + install + run)
├── requirements.txt    # Python dependencies
├── templates/
│   └── index.html      # Main page template
├── static/
│   └── css/
│       └── style.css   # Stylesheet (light/dark themes)
└── qrcodes/            # Generated QR codes (created at runtime)

Requirements

• Python 3.9+
• Dependencies (installed automatically via start.sh):
  • Flask >= 3.0.0
  • Werkzeug >= 3.0.0
  • qrcode[pil] >= 7.4.0
  • Pillow >= 10.0.0

License

MIT

Books by the Authors

Scan to check out our books on Amazon