QR code not working? 9 reasons and how to fix them
By manxlr · · 7 min read
You point your phone at the code and… nothing. Or worse, it opens the wrong page. Here are the nine most common causes, roughly in order of how often we see them, and how to fix each one.
1. The free trial ended (dynamic codes)
If the code used to work and suddenly opens an error, an ad, or an “upgrade” page, it was probably a dynamic code from a generator whose trial or plan has lapsed. Fix: make a new static code pointing at a URL you control — it will never expire.
2. It's printed too small
Below about 2 cm, or smaller than a tenth of the scanning distance, many phones can't resolve the modules. Check with the size calculator.
3. Not enough contrast
Light gray on white, yellow on white, or a code laid directly over a busy photo all fail. Use a dark foreground on a light background, and keep a solid background behind the code.
4. Inverted colors
Light code on a dark background looks stylish, but some scanners — especially older Android apps — don't support inverted codes. Swap the colors, or test on several devices.
5. No quiet zone
Text, borders or image edges touching the code confuse the scanner's finder. Leave margin around all four sides.
6. The logo is too big
Error correction can recover roughly 30% of a code at level H. A logo covering more than that — or covering the three corner squares — breaks it. Keep logos at 20–25%. See logo QR codes explained.
7. Too much data
Long URLs with tracking parameters make dense, fragile codes. Use a short, clean URL — or a short URL on your own domain.
8. The image was stretched
If someone resized the code without locking the aspect ratio, it's no longer square and may not scan. Re-place it with a tool that keeps it square, like the QR Brand editor.
9. The destination is broken
Sometimes the code is fine and the link isn't: a typo, a deleted page, or an http/https mix-up. Read the decoded content with the QR scanner to see exactly what's inside.
A 30-second pre-print checklist
- Scan the final file with two different phones.
- Read the decoded URL and open it — does it land on the right page?
- Print one copy at real size and scan from the real distance.
- Make sure there's a reason to scan nearby (“Scan for the menu”).