How Our QR Code Generator Works: Standards and Error Correction

QR code standard

Our QR Code Generator uses the QRCode.js library, which implements the ISO/IEC 18004 standard for QR code barcodes. QR codes can encode text, URLs, contact information, WiFi credentials, and other data in a 2D matrix of black and white modules.

QR code versions

QR codes come in 40 versions, from Version 1 (21x21 modules) to Version 40 (177x177 modules). The library automatically selects the smallest version that can hold the input data at the chosen error correction level. Larger versions hold more data but are harder to scan.

Error correction

QR codes use Reed-Solomon error correction, which allows the code to be read even if partially damaged. Four levels are available:

Data capacity

Maximum capacity at Version 40 with low error correction: 7,089 numeric characters, 4,296 alphanumeric characters, or 2,953 binary bytes. For reliable scanning, keep data under 200 characters when possible.

Standard compliance

Generated QR codes are compliant with ISO/IEC 18004 and can be read by any standard QR code scanner, including the built-in cameras of iOS and Android devices. The QR code specification is open and royalty-free.