Why did my QR code stop working?
A printed QR code that suddenly does nothing is usually one of eight problems. Here's how to tell which one you have, how to fix it, and how to stop it happening again.
· 5 min read
You printed the code, it worked for months, and now customers are telling you it doesn't. Or it never worked properly in the first place. Either way, the cause is almost always one of the eight below, and most take a minute to diagnose.
Quick test first: scan the code with two different phones, one iPhone and one Android, from about the distance a customer would. If neither phone reacts at all, the problem is the printed code itself (causes 5 to 8). If the phone reads it but the page is broken, missing or asks you to pay, the problem is where the code points (causes 1 to 4).
First: is it a static or a dynamic code?
This decides most of what follows. A static code stores your link, Wi-Fi password or text inside the pattern itself. Nothing sits between the customer and the destination, so no company can switch it off.
A dynamic (editable) code stores a short link that belongs to the company that made it, which then forwards customers to your real page. That's what lets you change it after printing, but it also means the code only works while that company keeps forwarding it.
To tell which you have, scan it and look at the address your phone shows before you open it. If it's your own website, it's static. If it's a short address from a QR company, it's dynamic.
Problems with where the code points
1. The free trial or subscription ended
This is the most common cause for dynamic codes, and the most frustrating. Some QR generators let you make editable codes free for a trial period, then switch them off, or send customers to an advert or a "this code has expired" page, until you pay. The code on your tables hasn't changed, but the company has stopped forwarding it.
How to tell: the address shown on scanning belongs to a QR company, and the page says the code is inactive, expired or needs upgrading.
How to fix it: log in to the account that made the code. Paying again usually brings it back immediately. If you'd rather not, make a new code you control and reprint. You can't move an existing printed code to another company, because the short link belongs to them.
2. The page it points to moved or was deleted
Static codes point straight at an address, so if your website was rebuilt, your menu PDF was replaced with a file of a different name, or a booking page was retired, the code now leads to a "page not found" error.
How to fix it: put the old address back, or ask whoever runs your website to redirect the old address to the new one. A redirect is the fastest fix because it saves reprinting. For a menu, avoid file names with dates in them, like menu-march.pdf. They're the ones that get replaced.
3. The Wi-Fi password or network name changed
A Wi-Fi code holds the network name and password inside it. Change either one, even just its capital letters, and every printed code stops connecting.
How to fix it: make a new code with the current details, using our free Wi-Fi QR code generator, and replace the printed ones. If you change the password often, use an editable Wi-Fi code that opens a page with the current password, so you can update it without reprinting.
4. The link was flagged as unsafe
Browsers and some QR services check links against lists of dangerous sites. If your website was hacked, or a link shortener's address got onto a blocklist, customers may see a red warning page instead of your menu.
How to fix it: open the link on a computer and see what warning appears. You can also check it with our QR code safety checker. If your own site is flagged, ask your web host to clean it up, then request a review through Google Search Console.
Problems with the printed code
5. It's printed too small
Phones need a few pixels per square to read a code. A code that's fine on a business card is too small on a poster across the room, and long links make codes denser, so they need more space. A good rule is about 1 cm of code for every 10 cm the customer stands away. See our QR code size guide for the numbers.
6. Not enough contrast
Pale codes, codes in your brand colour on a coloured background, and light codes on a dark background all fail on some phones. Scanners look for dark squares on a light background. Use a dark code on white, or at least on a very light colour.
7. The white border was cropped off
Every QR code needs a margin of plain background around it, called the quiet zone, about four squares wide. Designers often crop it to fit a layout, or place the code right against a photo or a border line. Put the white margin back.
8. It's damaged, curved or shiny
Scratches, fading in a sunny window, water damage on a laminated tent, a code wrapped around a curved cup, or glare from a glossy finish under restaurant lights can all stop a scan. QR codes can survive some damage, but not much. Reprint on matte paper and keep codes out of direct sun.
How to make sure it never happens again
- Use static codes for anything that won't change. Your website's home page, a review link, a Wi-Fi network you rarely change. They're free and permanent. Our QR code generator makes them with no sign-up.
- For editable codes, read the cancellation terms before you print. Check what happens to your codes if you stop paying. If the answer is "they stop working", every menu and table tent you print is a reason you can't leave.
- Test every print run with two phones before you put it out, and again every few months.
- Keep a list of what each code points to, where it's printed, and which account made it.
We built Qrunto because of cause number 1. Static codes work forever, and if you cancel Pro, your editable codes fall back to the free plan instead of being switched off.