QR code not working? 7 common causes and how to fix them

First: is it the link or the print?

Scan the code with your phone camera. If the phone shows a link but the page fails or shows an error or upgrade screen, the link is the problem. If the phone shows nothing at all, the print is the problem.

Link problems

• The dynamic code expired. Some QR generators deactivate codes when a trial or subscription ends. Fix: reactivate the plan or reprint with a code from a service whose free plan keeps codes live.
• The page moved or was deleted. A static code still points at the old URL. Fix: redirect the old URL on your website, or reprint. Use a dynamic code next time.
• The short link was deleted or edited by mistake. Fix: restore the destination in your link dashboard. The printed code works again straight away.

Print problems

• Too small. Rule of thumb: the code's width should be about one tenth of the scanning distance, and at least 2 cm for close-up use.
• Low contrast or inverted colours. Dark modules on a light background scan best. Light-on-dark codes fail on some older scanner apps.
• No quiet zone. The blank margin around the code is part of the code. Don't crop it or print right up to a border.
• Damaged, curved or glossy. Creases, wrapping around a bottle, or glare from lamination can all break a scan. Raise the error correction level or print the code flat and larger.

How to stop it happening again

Use a dynamic code so you can fix the destination without reprinting, from a vendor with a clear exit policy. Print a proof and test it on two phones in the light where it will hang. Use one link per placement so you can see which code stops getting scans.