How I Built a Barcode & QR Code Generator with No Backend (Vanilla JS)

Most barcode generators I found online had the same problems: 👉 Too many ads 👉 Slow performance 👉 Required signup So I decided to build my own. But with one rule: 👉 No backend. Everything runs in the browser. The Idea I wanted a tool that: Works instantly Requires no login Runs entirely client-side Supports multiple barcode formats Tech Stack I kept it as simple as possible: Vanilla JavaScript HTML + CSS No frameworks No API calls Everything is generated directly in the browser. Supported Formats The tool currently supports: EAN-13 Code128 UPC QR codes (WiFi, URL, email) How It Works Instead of sending data to a server: User enters input JavaScript generates the barcode It renders instantly on screen User downloads it No requests, no latency. Why No Backend? I chose this approach for a few reasons: Speed No API = instant response Privacy User data never leaves the browser Simplicity No server = less maintenance Challenges I Faced Barcode accuracy Ensuring the generated barcodes are sca