The Quick Response Code, defined

One-sentence definition

A Quick Response Code is a two-dimensional matrix symbology, invented in 1994 by Denso Wave and standardized as ISO/IEC 18004, designed for rapid decoding from any orientation.

Institutional definition

The Quick Response Code is a machine-readable optical label that encodes data within a square grid of light and dark modules. Three large position-detection patterns are set into the symbol's corners; together with alignment patterns, timing patterns, format information, and a surrounding quiet zone, they permit a scanner to locate, orient, and decode the symbol independent of rotation or moderate damage.

The symbology supports four primary encoding modes — numeric, alphanumeric, byte, and kanji — and four error-correction levels (L, M, Q, and H) drawn from the Reed–Solomon family. It is published in forty defined versions ranging from a 21 × 21 module symbol (Version 1) to a 177 × 177 module symbol (Version 40), the latter capable of carrying up to 7,089 numeric characters in a single symbol.

Authoritative references

The normative reference for the Quick Response Code is ISO/IEC 18004, first published in 2000 and revised in 2006 and 2015. The Japanese national standard is JIS X 0510. The originating organization is Denso Wave, a subsidiary of the Denso Corporation; Denso Wave holds the QR Code trademark.

The Quick Response Code is the subject of this reference. Subsequent pages document its history, technology, standards, types, applications, and the public infrastructure that has accreted around it.