Information about the QR Code generator QR Codes are two-dimensional bar codes in which information is depicted by black and white dots (so-called "square data dots" or "data pixels"). If the contrast between foreground and background is high enough and the image is not inverted, it is also possible to use colors. 2D barcodes can be compared to one-dimensional barcodes, as seen on products in supermarkets. In contrast to these barcodes, QR graphics can contain up to 3000 characters on a relatively small space. The information for the QR Code is encoded according to ISO/IEC 18004:2006. The high density of information and many available reader application make QR Codes an ideal marketing instrument: QR Code reading apps are available for almost every smartphone with a camera (e.g. iPhone, Google Android, Blackberry, Symbian).