Hand Drawn QR Codes

I really like QR codes. Recently I purchased a new sticky-note-like pad from a new local stationery store in Minneapolis. The sheets have a 10x10 grid and 2x10 grid.

I knew what I wanted to do, I wanted to create a QR code on a sheet. The smallest QR code (besides micro QR codes) is

Version 1 QR codes can hold URLs up to 17 bytes long using the lowest data quality setting. Unfortunately https://sethmlarson.dev is 23 bytes long, so I'll have to improvise. I went with sethmlarson.dev instead, as this will prompt many QR code scanners to "search" for the term resulting in my website.

Note that a lovely reader informed me shortly after publication that indeed I can include my full domain name in a version 1 QR code by using all capital letters instead of lowercase. TIL that the "alphanumeric" character set for QR codes actually contains symbols for URLs like : and /.

I created my reference using the qrcode package on the Python Package Index. Don't forget the -n option with echo to not include a trailing newline.

$ echo -n "HTTPS://SETHMLARSON.DEV" | qr --error-correction=L

I drew the corner squares (known as "position patterns") and then started trying to scan the QR code as a gradually filled in other pixels. Once I had drawn the "timing lines" between the top left and bottom left position I could see that my scanner "wanted" to see something in my drawing.

I continued adding the top timing line and data and then the scanner could start to see the whole square as a QR code. If you look closely I even made a mistake here in the data a bit, but in the end this didn't matter even on the lowest error-correction level.

Finally, my QR code was complete! Scanning the QR code was quite finicky because the paper was curling up off the flat surface. I could only get the scan to work when I held the paper flat. However, hanging the QR code from my monitor worked extremely well, even when scanning from a distance.

I hope this inspires you to try hand-drawing something on grid paper.