Why Is My QR Code Not Scanning? 10 Fixes
· 2 min read · Scanlexa team
A QR code that won't scan is frustrating for you and costly if it's already printed. Here are the usual causes, roughly from most to least common.
1. It's too small for the distance
The code should be at least a tenth of the scanning distance: 20 cm wide for a poster read from 2 metres. Use the size calculator and read what size a QR code should be.
2. Not enough contrast
Pale colours (yellow, light green, pastels) on white, or dark colours on black, are hard to read. Keep the pattern dark and the background light. See the best QR code colours.
3. The colours are inverted
A light pattern on a dark background confuses some phones. Swap them round.
4. The logo is too big
A logo covers part of the pattern. QR codes have built-in error correction that can recover up to 30% of the pattern at the highest level, but a logo over about a quarter of the width, or one with no margin, eats into that. Keep logos modest and leave space around them. Scanlexa switches to the highest error correction automatically when you add a logo.
5. No quiet zone
The blank border around the code must be about four squares wide. Text, borders or images touching the pattern stop scanners finding the edges.
6. Too much content
Long links and full contact cards create dense patterns with tiny squares. Shorten the link, or use a dynamic QR code, whose pattern only holds a short link.
7. A low-quality image
Blurry or stretched images, or low-resolution JPGs printed large, smear the squares together. For print, download a large PNG or (with Lifetime) an SVG or PDF, which stay sharp at any size.
8. Glare, curves or creases
Gloss lamination, curved bottles and folded flyers distort the pattern. Use matte finishes where you can, avoid folds across the code, and print larger on curved surfaces.
9. The link behind it is broken
Sometimes the code scans fine but the page doesn't load. Scan it yourself and check where it goes. With a dynamic code you can fix the destination without reprinting.
10. The code has expired or been paused
Dynamic codes can be paused or scheduled, and free dynamic codes on many services expire. On Scanlexa, a free dynamic code stays active for 30 days, then shows a page explaining how to reactivate it, rather than a dead link.
Check before you print
The Scanlexa designer scans your code in the browser after every change and blocks the download if it can't read it. You can also scan any image or screenshot with our free QR code scanner to see exactly what a code contains.