Pillar III
Technology
The Quick Response Code is defined by a precise technical specification. The pages collected here document each part of it.
The Quick Response Code is a two-dimensional matrix symbology whose symbols are constructed from light and dark modules arranged on a square grid. The pages below cover the symbol's structural anatomy, its position-detection (finder) patterns, its encoding modes, its error-correction scheme, the family of forty defined versions, the masking step applied to encoded data, the Reed–Solomon mathematics underlying error correction, and the surrounding quiet zone.
Pages in this section
Structure and anatomy
The constituent parts of a Quick Response Code symbol — finder, alignment, timing, format, version, data, and error-correction regions.
Finder patterns
The three position-detection patterns set into the symbol's corners and the 1:1:3:1:1 module-ratio that defines them.
Encoding modes
The four primary encoding modes: numeric, alphanumeric, byte, and kanji, and the mixed-mode chaining permitted within a single symbol.
Error correction
The four error-correction levels (L, M, Q, H) and the proportion of damage each is specified to recover.
Versions and sizes
The forty defined versions of the symbology, from Version 1 (21 × 21 modules) to Version 40 (177 × 177 modules), and their respective capacities.
Masking
The eight data-mask patterns that distribute light and dark modules to improve scanner reliability.
Reed–Solomon coding
The Reed–Solomon mathematics underlying the symbology's error-correction scheme.
Quiet zone
The minimum four-module margin of light modules that surrounds every symbol and the role it plays in detection.