QR Code Generator

A QR code (Quick Response code) is a two-dimensional matrix barcode developed by Denso Wave in 1994. It can encode text, URLs, contact information (vCard), Wi-Fi credentials, and other data using a grid of black and white squares. QR codes can be scanned in any orientation and even when partially damaged or obscured, thanks to three distinctive square markers in the corners that help the scanner establish orientation and scale.

QR codes use Reed-Solomon error correction, which allows recovery of data even when part of the code is damaged. Four error correction levels are available: L (recovers up to 7% of data), M (15%), Q (25%), and H (30%). Higher error correction levels increase the code's size and density but make it more resilient. For printed codes that may be folded or partially covered, higher error correction is recommended.

The data capacity of a QR code depends on the type of data and error correction level. Numeric data (up to 7,089 digits) is most efficient because it uses a 3.32-bit encoding per digit. Alphanumeric data (uppercase letters, digits, and a few symbols) can store up to 4,296 characters. Binary data (arbitrary bytes including UTF-8 text and URLs) can hold up to 2,953 bytes. For URLs, keeping them short — ideally using a URL shortener for long addresses — improves scanability when the code is printed at small sizes.