A QR Code, Step By Step

Have you ever wondered how QR codes work? There are plenty of dry technical guides out there, but if they’re not your thing you might find Nayuki’s step-by-step guide to be of interest. It explains the encoding and error checking bit generation process before starting on the familiar three-squares pattern and timing bars of the QR code itself. The really interesting part comes with its explanation of overlays, a set of repeating patterns that are added to the final data segment, and how the pattern used is chosen to minimise penalties due to large blocks of the same colour in the final piece. The chances are most of us will never have to create a QR code from scratch, but it is this type of fascinating technical general knowledge that makes guides like this such an interesting read.