Sput's QR

Sput QR

The above image was made with qrencode (which is also available as Debian package). It's a 21x21 'alphanumeric' QR code which contains the text 'HTTP://SPUT.NL/' and has error correction level 'Q'.
Using upper case only can reduce the amount of data, as can be seen below;

SPUT.NL QR sput.nl QR www.sput.nl QR
HTTP://SPUT.NL/ http://sput.nl/ http://www.sput.nl/

The webbrowser converts 'HTTP' into 'http', hostnames are case insensitive and my webserver redirects 'sput.nl' to 'www.sput.nl'. Not all QR readers support upper case URLs, but most do. If your QR reader doesn't understand the left QR try the other ones.
Files and paths are case sensitive though. So HTTP://EXAMPLE.COM/FOO/BAR and HTTP://EXAMPLE.COM/foo/bar are not the same thing!

More info;