Why is my QR code not scanning?

Almost every unscannable code fails for one of six reasons: it is printed too small for the scanning distance, the contrast is too low (or inverted — light code on dark background), the white margin around it is missing, heavy styling or a logo has eaten the error-correction headroom, glare or a curved surface is distorting the pattern, or the code scans fine but the link behind it is dead. Work through them in that order — the physical causes take seconds to check.

Why does my QR code say it has expired?

An 'expired' message means the code is dynamic: it points at a redirect service, and the service has stopped forwarding — usually because a free trial ended or a subscription lapsed. The printed pattern is fine; the middleman is gone. The fix is to generate a static code, where the destination URL is encoded directly in the pattern itself. A static code has no service behind it and cannot expire.

What size does a QR code need to be to scan?

Rule of thumb: the code's width should be at least one tenth of the distance it will be scanned from. A code on a table card scanned from 25 cm needs about 2.5 cm; a poster scanned from 2 metres needs about 20 cm. Never print below 2 × 2 cm, and give dense codes (WiFi credentials, vCards) extra size because their tighter pattern is harder for cameras to resolve.

Do QR codes stop working over time?

Static codes do not — the content is baked into the printed pattern, so a static code from ten years ago still scans. Dynamic codes stop working whenever the redirect service behind them shuts down, deletes the link, or ends your plan. Physical wear is the only ageing that affects static codes: fading ink and scratched laminate lower contrast, and reprinting fixes that.

Guides2026-08-11

Why your QR code isn't scanning

A QR code that will not scan is either a printing problem or a plumbing problem. The printing causes take seconds to check; the plumbing one — a dead redirect — is the one that quietly kills codes that used to work.

The one-minute diagnosis

Scan a screenshot of the original file. If the digital version scans and the print does not, the problem is physical: size, contrast, margin, or glare.
If the digital version also fails, the pattern itself is broken — usually over-styling or a logo that ate the error-correction budget. Regenerate with less decoration.
If it scans but nothing loads, the code is fine and the link is dead. If it was made with a “free” dynamic-QR service, the trial likely ended and the redirect was switched off.

Cause 1: too small for the distance

Cameras need enough pixels of pattern to lock on. The working rule: the code’s printed width should be at least one tenth of the scanning distance. A 2 cm code on a poster read from across a room will never scan, no matter how long the customer hovers. And 2 × 2 cm is the absolute floor even up close — below that, ordinary phone cameras hunt for focus and give up.

Density multiplies the problem. A code holding WiFi credentials or a full contact card packs far more modules into the same square than a short URL does, so give data-heavy codes half again as much space. If you can shorten what the code contains, do — a short clean URL produces the most forgiving pattern there is.

Cause 2: contrast and inversion

Scanners want a dark pattern on a light background. Brand-coloured codes fail when the two tones drift too close — mid-grey on white, orange on yellow, anything pastel on anything pale. And inverted codes (white pattern on a dark card) fail outright on many phones: plenty of camera apps simply do not try the inverted reading.

Quick test: squint at the code, or photograph it and drop the saturation. If the pattern does not jump out in black-and-white, a camera will struggle too. Style the corners and shapes if you like — but keep the tones far apart and the background lighter.

Cause 3: no quiet zone

The white margin around a QR code is not decoration — it is how the scanner finds the code’s edges. Designs that crowd text, borders, or background art right up against the pattern routinely break scanning. Leave a margin of at least four modules (roughly the width of one of the three corner squares) clear on every side, in the same light colour as the code’s background.

Cause 4: over-styling and logos

QR codes survive damage because of built-in error correction — the pattern carries redundancy, so a scratch or a centred logo can be reconstructed around. But that headroom is a budget: a big logo, heavy corner styling, and rounded custom modules can spend it all, leaving nothing for real-world wear. If a styled code fails while its plain version scans, remove decorations one at a time until it recovers, and always re-test after styling.

Cause 5: glare, curves, and wear

Glossy laminate under a ceiling spotlight reflects a white stripe straight across the pattern. Matte lamination scans identically and glares far less.
Curved surfaces — bottles, mugs, sleeves — bend the pattern. Keep codes on the flattest face and print them smaller than the flat area, never wrapping an edge.
Fading and scratches lower contrast over months in sunlight. The code has not “expired” — it has worn. Reprint from the original file and it works again.

Cause 6: the code scans, but the link is dead

This is the failure that confuses everyone, because the camera reads the code perfectly — and then the phone lands on an error page, a “this code has expired” notice, or a stranger’s upgrade prompt. It means the code is dynamic: it points at a redirect service, not at your actual page, and the service has stopped forwarding. Free trials ending is the classic cause — printed menus and flyers die in bulk the day the plan lapses. Worth checking the other meter too: if the plan is current and the code still lands on an upgrade prompt, you have probably hit a monthly scan cap, which fires on the busiest day rather than a predictable one.

There is no repair for a printed dynamic code whose service is gone; the middleman’s address is baked into the pattern. The durable fix is to regenerate the code as a static one, where your URL itself is encoded in the pixels. No service, no account, nothing to lapse — if the destination page is up, the code works. Full explanation: do QR codes expire?