Your QR code looks fine, but scanning is hit or miss. Here are the failure modes, ranked by how often they're actually the cause.
1. The QR is too small (most common)
The 1:10 rule: your QR should be roughly 1/10th of the scan distance. A 1-inch QR is for scanning from arm's reach. A storefront QR scanned from across the sidewalk needs to be 4+ inches.
Fix: Measure your scan distance, divide by 10, that's your minimum QR size.
2. Poor contrast
Black on white scans best. Anything else scans worse. Light gray on white, yellow on white, white on light blue — all bad.
Fix: Aim for a 4:1 contrast ratio between the QR and its background. If unsure, just use black.
3. Damaged or crumpled print
Folded business cards, scratched stickers, faded inkjet prints — all reduce scan reliability.
Fix: Reprint, ideally on cardstock or vinyl. Order from a professional printer for batches over 50.
4. Logo is too big
A logo that eats more than ~25% of the QR area destroys too much data for error correction to recover.
Fix: Shrink the logo, or remove it entirely as a test.
5. No quiet zone
The blank margin around the QR (at least 4 modules wide) is required. Without it, scanners can't find the code.
Fix: Add white padding around the QR, equal to about the width of a finder square.
6. Glare or reflection
Glossy paper, laminated stickers, screens, glass storefronts — all create glare that confuses the camera.
Fix: Use matte finishes when possible. For glass, position the QR where reflections are minimized.
7. Inverted colors
White-on-black QR codes work on iPhones but not always on Android. Don't invert without testing.
Fix: Use dark-on-light unless you've thoroughly tested the inverted version on multiple devices.
8. The destination URL is broken
Sometimes the QR scans fine — the URL just doesn't load. 404s, expired domains, broken redirects. Always test the actual landing experience, not just the scan.
Fix: With OneDollarQRcodes you can update the destination URL via email request — even after printing. Without that, you reprint.