I used stitchfiddle to make a qr code for a message for my best friend and it actually works and I haven't been this proud of a project in a while! Word of advice if you decide to do this, use dc and and use 2 for each square. And doing this you will need to double your starting chain but it's 100 percent worth it. Also don't be like me...write it out as a pattern first ????‍♀️???? I just used some left over yarn I had so I have no clue what brand it is, but it's definitely worsted weight!