Why your QR code isn't scanning: 9 fixes

You printed 500 menus. Nobody can scan the QR. Before you reprint, work this list.

1. The size is too small. Below 2cm × 2cm, most cameras struggle. Below 1.5cm, almost no scanner works. Rule of thumb: print width = scan distance / 10.

2. The contrast is too low. Light grey on white = scanner can't see the modules. Always use dark QR on light background (or vice versa). Avoid pastel-on-pastel.

3. You used inverted colors. Light QR on dark background works in theory, but many older Android scanners reject it. Default to dark-on-light unless you have a good reason.

4. The logo is too big. A logo covering more than 30% of the centre breaks too many modules. Keep it under 25% and only on QRs generated with high error correction (mode H).

5. The paper is reflective / glossy. Glare from overhead lights blinds the camera. Always test print on matte. Vinyl stickers should be matte finish.

6. You mirror-flipped the image. Some print shops accidentally mirror QRs. Mirrored QRs cannot be scanned. Always test scan a printed sample before mass-printing.

7. The destination is broken. Visit the destination URL in your browser. If it 404s or redirects somewhere weird, fix the URL — the QR is fine, the target isn't.

8. The QR is dirty / damaged. A QR can tolerate ~30% damage thanks to error correction, but anything beyond that breaks scanning. Reprint if you see ink smudges or tears across the finder patterns.

9. The light is wrong. Test in real-world lighting (your customer's cafe table, not your design studio). Some QRs that scan perfectly under bright office lights fail under dim restaurant lighting.

One more thing: before printing 10,000 copies, print 1 sample, scan it from your phone at the expected distance, and have a friend with a different phone OS do the same. Five minutes of test-scanning prevents ₹50,000 of reprints.