QR Code Not Working?
Short answer: check size, contrast, quiet zone, and image resolution first. If the code scans but goes nowhere, the link behind it's dead. Seven causes, seven fixes. Most take under a minute.
Seven reasons a QR code fails to scan
1. Too small
A rough guide: one inch of code for every ten inches of scanning distance. Anything smaller than about 2 cm is going to struggle at arm's length.
2. Low contrast
The scanner needs dark modules on a light background. Pastel colors, light-on-light schemes, and inverted designs (light code on dark background) all cause misreads.
3. No quiet zone
A QR code needs a blank margin of about 4 modules on all four sides. Crop it tight and the scanner can't find where the pattern starts.
4. Pixelated image
Scaling up a low-resolution PNG blurs the modules. Re-download a high-res PNG or SVG from the generator and resize from that master file.
5. Error correction too low
A scratched, folded, or logo-covered code needs a higher error-correction level (Q or H) to recover. Low correction (L) won't survive much physical damage.
6. Device or app issue
Camera permission off, or an old phone that doesn't scan natively. Check permissions first. If that's fine, a free QR scanner app usually fixes it.
7. Dead destination link
The code scans fine but lands on a 404. The code isn't broken. The link behind it's rotted. This one has a clean fix without reprinting.
The dead-link fix: update without reprinting
A static QR code bakes the URL in forever. If that URL changes or goes down, the code is stuck. You'd have to reprint everything.
A dynamic QR code works differently. It points to a short redirect you control, and you can change where that redirect goes at any time. The printed code stays exactly the same. Free with a free account: no reprinting, no downtime, no charge.
The free plan includes five editable codes. Change the destination as many times as you need.
Getting the image right for print
If your code is blurry or pixelated, the generator is the starting point. Download SVG for anything that needs to scale, or a high-resolution PNG if the destination format requires raster. Then resize from that file. Never export a small image and scale it up in a design tool.
ProQR.codes gives you SVG and high-res PNG on every code, no account required. Start at qr-types or go straight to the URL QR generator.
Quick diagnostic
| Symptom | Likely cause | Fix |
|---|---|---|
| Camera won't focus on it | Too small or too close | Print larger, or step back |
| Scans but goes to a 404 | Dead destination link | Dynamic code, update the link |
| Works on one phone, not another | Device/app support | Install a QR scanner app |
| Never worked since printing | Low-res export, no quiet zone | Re-export SVG or high-res PNG |
| Worked before, stopped working | Link changed or rotted | Repoint with a dynamic code |
| Logo in middle, partial scan | Error correction too low | Regenerate with level Q or H |
QR code scanning FAQ
The most common causes: the code is too small, the contrast is too low, there's no quiet zone (blank margin), or the image is pixelated. If the code scans but goes nowhere, the destination link is dead. Each of those has a different fix, and most take under a minute.
First, check that your camera app has permission to access the camera. On older phones the built-in camera doesn't read QR codes at all. You'll need a separate QR scanner app. Also check you're holding the phone steady and there's enough light.
On iPhone, QR scanning is built into the Camera app but requires camera permission and iOS 11 or later. On modern Android phones it's usually built into the camera app too, though the exact version varies by manufacturer and some put it behind a settings toggle. If neither works, a free QR scanner app solves it.
If the code used to work, the most likely cause is a dead destination link. The code itself is fine. With a dynamic QR code (free with a free account), you can update the destination without reprinting. If the code never worked, check size, contrast, quiet zone, and image resolution.
Related: do QR codes expire and all guides.