You point the camera at the code and nothing happens. Most of the time the fix takes ten seconds. Work down this list in order: the first fixes are about your iPhone, the last ones are about the code.
Fixes on your iPhone
1. Turn on QR scanning
Open Settings › Camera and make sure Scan QR Codes is on. It’s on by default, but updates, a new phone setup or someone else using your phone can switch it off.
2. Use the right camera mode
Use the normal Photo mode on the back camera. Portrait, Cinematic, Pano and the front camera don’t always pick up codes.
3. Wipe the lens
A thumbprint or pocket dust blurs fine detail. Small codes are the first thing to fail. A quick wipe with a soft cloth fixes more scans than you’d expect.
4. Change the distance
Holding the phone too close is the most common mistake. The whole code, including a little white space around it, has to fit on screen and be in focus.
- Start about 15 to 30 cm (6 to 12 inches) away, then move slowly closer.
- For posters and signs, step back. A rough rule: you can scan from about ten times the code’s width.
- Recent iPhones may switch to the macro lens up close, which can make the image jump. Move back a little and let it settle.
5. Fix the light
Glare on glossy menus, shadows from your own hand and dim restaurants all cause failed scans.
- Tilt the phone a few degrees to move the reflection off the code.
- Use the torch: the Scan Code control in Control Center has its own torch button.
- For a code on a screen, lower that screen’s brightness and step back to avoid stripes.
6. Check Screen Time and restarts
If the Camera app is missing or won’t open, check Settings › Screen Time › Content & Privacy Restrictions › Allowed Apps and make sure Camera is allowed. If everything looks right and it still fails, restart the iPhone and install any pending iOS update.
7. Try a different scanner
The Camera, the Scan Code control and scanner apps each read codes a little differently. If one fails, try another. A dedicated scanner app such as QR Code Scan Kit shows the full content of every code, not just a short preview, and reads barcodes, which the Camera app isn’t made for.
When the problem is the code
If none of the above helps, the code itself is probably the problem. These are the usual faults:
8. It’s damaged or covered
QR codes have built-in spare data called error correction. Depending on the level the maker chose, a code can still be read with roughly 7% (level L) up to 30% (level H) of it damaged or hidden, according to Denso Wave, the company that invented the QR code. Scratches across the three large corner squares are the hardest to survive, because scanners use them to find the code.
A logo pasted in the middle eats into that spare data. If the maker used a big logo with a low error-correction level, the code may fail on every phone.
9. It has no blank border, or too little contrast
Scanners need a clear margin around the code, called the quiet zone. The QR standard asks for four modules (four of the small squares) of empty space on every side. Codes squeezed against a photo, a frame or the edge of a label often fail.
Contrast matters too: dark modules on a light background work best. Light grey on white, colour on colour, or a code printed in light ink on a dark background can trip up some scanners.
10. It’s too small or too dense
A long web address makes a dense code with many tiny squares. Printed small, those squares blur together. Shorter content (or a shorter link) makes a simpler code that scans from further away.
Test a code that won’t scan
If you have a picture of the code, our free QR code not scanning checker looks at it in your browser and points out the usual problems: size, contrast, blur and a missing border. It’s useful before you print 500 flyers, too.
Sources
- Denso Wave (QRcode.com): Error correction feature
- Apple Support: Scan a QR code with your iPhone or iPad
