qr – generate QR code


qr [ -LMQHna ] [ -v version ]


Qr generates a QR code from the data it reads on standard input. The QR code is generated as an image(6) on standard output.

The -LMQH options set the level of error correction. -L is the lowest and -H is the highest level. The default is -M.

The QR standard defines different sizes labelled version 1 to version 40. By default the smallest possible is chosen automatically. The -v option forces the use of a particular version.

By default bytes are encoded directly with no translation. Coding efficiency can be increased by reducing the set of legitimate characters using the -an options. The -n option supports only numbers and the -a option supports letters, numbers, spaces and the symbols $%*+-./:. Note that all letters are converted to upper case. Both options ignore any characters they do not recognize.




International Standard ISO/IEC 18004.


The standard specifies the use of JIS-8 encoding in the default mode, however rumour has it that readers recognize UTF-8.

The more advanced coding features (Kanji mode, extended modes, switching modes midstream) are not supported.