QR codes are pixelated black and white squares that perform magic when we point the cameras on our phones at them—but what’s going on that makes this little spell possible? QR codes are akin to the ...

QR codes have a wide range of uses that help people avoid contact with objects and close interactions with other people, including for sharing restaurant menus, email list sign-ups, car and home sales ...

How big your code should be printed depends on how many characters you “encode” into it. It can take an absolute maximum 7,000 characters, but realistically most people will encode about 20 letters or ...