QR Code encoding library Libqrencode is a library for encoding data in a QR Code symbol, a kind of 2D symbology that can be scanned by handy terminals such as a mobile phone with CCD. The capacity of QR Code is up to 7000 digits or 4000 characters, and has high robustness. Libqrencode supports QR Code model 2, described in JIS (Japanese Industrial Standards) X0510:2004 or ISO/IEC 18004.