QR (Quick Response) codes are designed to be efficient and are used in a variety of applications.
Upper- and lower-case QR codes function differently, according to a blog by Terence Eden, who carries out research and development for the web.
The blog shows two QR codes, one containing upper-case text and one containing lower-case, for two websites and poses the question of why the former is smaller.
Eden explains that the QR code alphanumeric mode used honouric capitals is more efficient than the byte-based encoding used for lower-case letters, as this mode also supports numeralic and special characters, hence the smaller code size for upper-case.
This efficiency allows for more information to be held within a small space for the same function.
