Why Is My QR Code Not Scanning? 12 Fixes
When a QR code does not scan, it is almost always one of a small number of problems. Work through this list in order; most issues are found in the first five checks.
1. Not enough contrast
Scanners look for dark modules on a light background. Pale colors, gradients that fade to light, or a dark background with a dark code all cause failures. Aim for a contrast ratio of at least 4.5:1; QRizeo’s preview warns you when contrast is low.
2. Inverted colors
A light code on a dark background looks stylish, but many phone cameras and older scanner apps cannot read inverted codes. If you need a dark design, put the code on a white panel.
3. No quiet zone
The blank border around the code is part of the code. Text, a frame line or a photo touching the edge stops scanners finding it. Keep four modules of empty space on every side.
4. Printed too small
Use roughly one tenth of the scanning distance as the minimum width, more for dense codes. Our size guide and calculator go into detail.
5. Too much data
A very long link or a contact card with every field filled creates a dense grid of tiny modules. Shorten the link, remove optional fields, or print larger.
6. Logo too large
A logo hides part of the data. Error correction can rebuild up to about 30% at level H, but only if the logo stays well under that. Keep the logo below about a fifth of the width and never over the three corner squares.
7. Blurry or stretched image
Enlarging a small PNG, or stretching a code to fit a space, blurs or distorts the modules. Use SVG, keep the aspect ratio square, and do not apply effects such as blur or drop shadows.
8. Reflections and curves
Glossy lamination, shop windows and curved bottles bounce light into the camera. Use matte finishes where possible and print a little larger on curved surfaces.
9. The code scans but the destination fails
If the phone reads the code but shows an error, the problem is the content: a mistyped link, a deleted file, a private Google Drive document, a changed Wi-Fi password. Scan the code and read exactly what it contains — our scanner shows the raw content.
10. Wrong Wi-Fi details
Wi-Fi codes fail silently when the network name has different capitals, the password has a typo, or the security type does not match the router. Check each against the router settings.
11. Old phones and camera apps
Very old phones need a scanner app or Google Lens. Some built-in camera apps also ignore codes that take up a small part of the frame; ask people to move closer.
12. Damage and wear
Scratched table cards, faded outdoor signs and folded flyers lose modules. Laminate codes that get handled, and replace outdoor codes before they fade.
A quick pre-print checklist
- Dark code, light background, no inversion.
- Clear margin on all four sides.
- Printed at least 2 cm, and about one tenth of the scanning distance.
- Logo small and centred, error correction H.
- Content checked: link opens on mobile, file is public, Wi-Fi details match.
- Tested with two different phones at the real distance.