QR code expired or stopped working? Find the cause and fix it

Start here: find out what the code contains

Before changing anything, upload a photo or screenshot of the code to the QR code reader. It decodes the image in your browser without opening the link and shows exactly what is inside. That sorts the problem into two halves: the code decodes and the trouble is where it points, or it does not decode and the trouble is the print or the scanner. The eight causes below run in order of likelihood.

1. It was a dynamic code and the trial or subscription ended

This is the most common reason a QR code stops working, by a wide margin. Many popular generators create dynamic codes: the pattern holds a short address on the vendor’s domain, and the vendor’s server forwards scans to your page. When the trial ends or the plan lapses, the forwarding stops and every printed copy dies at once. The static vs dynamic explainer covers the mechanics.

How to check

Decode the code with the reader. If the result is a short address on a domain that is not yours, typically a few letters followed by a slash and a random string, it was dynamic. Opening that address in a browser usually shows an error page or a request to upgrade.

Fix

Make a static code that points directly at your page and reprint. The generator on the home page embeds the address in the code itself, so there is no service to lapse. To keep the option of changing the destination later, encode a page on your own domain and change what it forwards to.

2. The destination URL is dead or moved

The code decodes to your own address, but the page behind it has been deleted, renamed or moved to a new site. This happens after website redesigns, when a menu PDF is replaced with a new file under a different name, or when a hosting plan is cancelled.

How to check

Copy the decoded address into a browser. A 404 page, a “site cannot be reached” error or a redirect to a homepage means the destination has changed.

Fix

Restore the page at the original address, or set up a redirect from the old address to the new one on your own site. Both options keep the printed code working. If neither is possible, generate a new code for the new address and reprint.

3. A broken redirect or link shortener

Codes made from a public link shortener behave like dynamic codes: they depend on the shortener staying in business and keeping your link active. Some delete unused links after a period, some have shut down, and some show an interstitial page that confuses people.

How to check

If the decoded address belongs to a shortening service rather than to you, open it and follow the chain. If it stalls, warns, or lands somewhere unexpected, the redirect is the problem.

Fix

Encode the full destination, or a short path on your own domain that forwards to it. Your own domain is the only shortener nobody else can turn off.

4. Low contrast or poor print quality

Scanners need dark modules on a light background with a clear difference between the two. Pale grey on white, brown on beige, a faded print, a photocopy of a photocopy, or ink that has bled on cheap paper all reduce contrast until the phone cannot separate the modules.

How to check

Photograph the printed code in ordinary light and upload it to the reader. If a clean digital file decodes but the photo of the print does not, the print is the weak link. The generator’s contrast checker also warns when a colour choice falls below a safe ratio.

Fix

Reprint with black or a very dark colour on white or a very light background, at a size where each module is at least 0.5 mm. Use the SVG or PDF export for anything a print shop will handle so nothing is resampled.

5. Inverted colours (light on dark)

A white code on a dark background looks striking and fails on a large share of phones. The QR standard defines dark modules on a light background, and while some scanner apps detect inverted codes, the built-in camera apps most people use often do not.

How to check

Look at it. If the modules are lighter than the background, it is inverted. Test with the default camera app on both an iPhone and an Android phone rather than a dedicated scanner app.

Fix

Swap the colours so the modules are dark. If the design needs a dark background, place the code on a light panel with a proper quiet zone around it.

6. Damaged or missing quiet zone

The quiet zone is the blank margin around the code, four modules wide on every side. Designers frequently crop it away, run text or a border right up to the edge, or place the code on a busy photograph. Without it the scanner cannot find where the code starts.

How to check

Measure the blank space around the code. It should be at least four times the width of one small square, and it should be the same colour as the code’s background.

Fix

Re-export with the quiet zone included (the generator defaults to four modules) and keep design elements outside it. If the code is already printed inside a frame, a white sticker with a fresh code is cheaper than arguing with a scanner.

7. The code is too small or too dense for the distance

A code that scans from a phone held 20 cm away can be unreadable from two metres. Dense codes, such as a full contact card or a long URL with tracking parameters, have many small modules and need more width for the same distance.

How to check

Scan from the distance people actually use. If it works up close and fails from where it is mounted, size is the problem. The size guide has a calculator: as a rule the width should be at least one tenth of the scanning distance.

Fix

Print larger, or shorten the content so the code has fewer modules. A short path on your own domain turns a 60-character URL into a 25-module code.

8. The phone or app cannot read it

Occasionally the code and the print are fine and the phone is the problem. Android phones from before version 9 or 10 often have no scanner in the camera app, some cameras need the QR setting switched on, and a smudged lens can defeat any code.

How to check

Try a second phone. If a modern iPhone or Android phone reads the code immediately, the first phone needs a scanner app or a clean lens.

Fix

Print a short instruction next to the code (“open your camera and point it here”), and for older phones, the web address in plain text beneath it so nobody is stuck.

What “QR code expired” really means

A QR code has no expiry date. It is a picture of text, and the picture does not change. When a code that used to work stops, one of three things has happened: the service forwarding it has ended (causes 1 and 3), the page it points to has gone (cause 2), or the physical code has become unreadable (causes 4 to 8). The first is by far the most frequent, and it is the one this site exists to prevent: every code generated here is static, verified by decoding it before download, and free of any server that could later be switched off.