QR code not scanning

A QR code that will not scan almost always has one of nine causes. Work through them in order — the first three account for most failures.

Work through these in order. The first three are the cause the overwhelming majority of the time.

1. Not enough contrast

Scanners need a clear difference between the dark modules and the light background. Mid-grey on white, two similar brand colours, or a code over a photo will all fail unpredictably — often working on one phone and not another.

Fix: dark foreground, light background, nothing behind it.

2. It is too small for the distance

A code is read from a distance roughly proportional to its size. A code on a table tent works at arm's length; the same size on a wall three metres away does not.

Fix: as a starting point, the code's width should be about a tenth of the distance it is read from. Full numbers in What size should a QR code be for print.

3. No quiet zone

QR codes need clear space around them — the "quiet zone" — so the reader can find the edges. Text, a border, or artwork pressed right up against the pattern will break it.

Fix: leave clear margin all round, at least four modules wide (about 10% of the code's width).

4. The logo is too large

A centre logo eats into error correction. Past roughly 30% of the width there is nothing left to recover with.

Fix: shrink the logo and raise error correction to the highest level. See Add a logo to a QR code.

5. It is inverted

Light modules on a dark background is the reverse of what most readers expect. Some handle it, many do not.

Fix: use dark-on-light.

6. Print quality or material

Ink bleed on uncoated stock, a glossy laminate that reflects, a curved bottle, or a code across a fold will all interfere.

Fix: print larger, avoid folds and curves, and prefer matte over high-gloss for anything people scan under bright lights.

7. The image was resized badly

Scaling a small PNG up produces soft, blurry edges. Scaling in a word processor is a common culprit.

Fix: always download at the size you need rather than enlarging afterwards.

8. The destination is broken

The code scans fine, but the page does not load. This looks identical to a scanning problem to whoever is standing there.

Fix: open the link in a browser yourself. If it is a uYou short link, check it is still active and has not expired — see My short link is not working.

9. The URL was wrong when you generated it

A typo, a missing https://, or a staging address that is no longer reachable.

Fix: scan your own downloaded file and read the URL it produces before it goes anywhere.

Test properly, once

Before any print run, scan the actual downloaded file, at final size, from realistic distance, on at least two different phones, in ordinary light rather than at your desk. That five-minute check catches nearly everything on this page.

Last updated 2026-08-24