Guides

What to know before sending a QR code to print — written from the measurements taken while building this tool.

• Why a printed QR code suddenly stops working

  The difference between static and dynamic codes, why a "free" code can die after printing, and how to check before you print a thousand of them.

• How small can you print a QR code

  How print size, content length and scanning distance relate — with concrete numbers so you do not have to print test sheets.

• Error correction and the logo in the middle

  Why "30% error correction" does not mean you can cover 30% of the area, and how large a logo can safely be.