|Summary: The QR code is the most popular 2D code, this article describes alternative codes that can also hold a lot of data relative to the print space they require.|
A 2D code is a two-dimensional code that contains data that can be read by a 2D code compatible scanner or by a smart phone, a feature phone, or a camera phone. Sometimes 2D codes are mistakenly called 2D bar codes. However, 2D codes contain pixels (picture elements) and bar codes are made up of vertical bars of varying widths.
There are several differences in these code formats. ScanLife EZcode and Microsoft Tag are proprietary formats only decodable by their programs, while the DataMatrix and QR code formats are open standard.
As of this writing (Feb 2012) The “QR code” dominates the market. QR has become a common term used to reference any 2D barcode (2D code, mobile tag, mobile barcode, etc.) even when codes are technically a different format. Even the @MicrosoftTag uses the #QRcode hashtag on Twitter.
Below is a more complete list of QR code alternative codes that may be suitable as QR code replacements because, like QR codes, they hold a lot of data relative to the space they take to print.