QR Code

The quick response, or QR, Code is a two-dimensional version of the Barcode able to convey a wide variety of information almost instantly with the scan of a mobile device.

One can encode URLs, Contacts (in vCard format), WiFi-Credentials, Locations or other ASCII data.

Creating QR Codes

You can create QR Codes with qrencode. Usage: qrencode [-o FILENAME] [OPTION]... [STRING] Encode input data in a QR Code and save as a PNG image.

OptionDescription
-o FILENAME, --output=FILENAMEwrite image to FILENAME. If ’-’ is specified, the result will be output to standard output.
-r FILENAME, --read-from=FILENAMEread input data from FILENAME.
-s NUMBER, --size=NUMBERspecify module size in dots (pixels). (default=3)
-l {LMQH}, --level={LMQH}specify error correction level from L (lowest) to H (highest). (default=L)
-m NUMBER, --margin=NUMBERspecify the width of the margins. (default=4)
-d NUMBER, --dpi=NUMBERspecify the DPI of the generated PNG. (default=72)
-c, --casesensitiveencode lower-case alphabet characters in 8-bit mode. (default)
-i, --ignorecaseignore case distinctions and use only upper-case characters.