1. The QR code is too small
A code that scans on a monitor may fail when printed very small. The farther away the user will scan, the larger the code should be. Test the real printed size rather than judging only from a design preview.
2. There is not enough contrast
Dark modules on a light background are the safest combination. Pale colours, gradients, textured backgrounds and transparent overlays can reduce contrast and make detection unreliable.
3. The quiet zone was cropped
QR codes need clear space around the outside. If a designer crops tightly to the black squares or places text and graphics too close, scanners may struggle to identify the code boundary.
4. The code became blurry
Resizing a small QR image upward, saving it as a heavily compressed JPEG or placing it into a low-quality social-media image can soften the square edges. Generate a larger PNG instead of enlarging a tiny code.
5. The printed surface is causing reflections
Glossy menus, curved packaging, glass and reflective signs can introduce glare. Test from several angles and under the lighting where people will actually scan it.
6. The code is damaged or partly covered
QR error correction can tolerate some damage, but large logos, stickers, folds or cropped corners can exceed that tolerance. Keep decorative changes conservative.
7. The camera cannot focus
Move slightly farther away and allow the camera to focus. Very close scanning can be harder than expected, especially with large printed codes.
8. The QR scans, but the destination is the problem
If the scanner reads the code but the link fails, the QR itself is working. Check that the URL is correct, uses HTTPS where appropriate and is still live.
How should I test a QR code before publishing?
First scan the saved image using QR Code Scanner. Then scan the final printed or displayed version with at least two different phones. Test at the distance and lighting users will encounter.