QR code not scanning? 10 causes and fixes
By Prabhneet Singh Narula, founder of RelyQr · Updated
Short answer
Most QR codes that won't scan fail for a handful of reasons: poor contrast, a code printed too small for the distance, no clear margin around it, a glossy or curved surface, a logo covering too much, or too much data making the pattern dense. Check them in that order; each has a simple fix.
The 10 most common causes
- 1
Low contrast
Phones need dark dots on a light background. Pale colours, grey on grey, or a busy photo behind the code all stop scans. Keep the dots dark and the background light.
- 2
Inverted colours
Light dots on a dark background are allowed by the QR standard, but many cameras and older scanners don't read them. Use dark on light.
- 3
Too small for the distance
Make the code about a tenth of the distance people scan from, and never smaller than 2 cm (0.8 in). See the size guide.
- 4
No quiet zone
The code needs a clear margin about four dots wide on every side. Text, borders or images touching it confuse cameras.
- 5
Too much data
Long links and long text make a dense pattern of tiny dots. Shorten the link, or use a dynamic code: its short link keeps the pattern simple.
- 6
A logo that covers too much
Keep a logo under about a quarter of the code, in the middle, away from the three corner squares, with error correction set to high. See adding a logo.
- 7
Glare and gloss
Shiny laminate, glass and screens reflect light into the camera. Use a matte finish, or tilt the code away from lights.
- 8
Curved or creased surfaces
Bottles, cups and folds bend the pattern. Print it bigger on curved surfaces and keep it off folds.
- 9
Damage and dirt
Scratches, stains and fading can remove too much of the code. Clean it or reprint it; laminate codes that live outdoors.
- 10
QR scanning switched off
On iPhone, check Settings › Camera › Scan QR Codes. On Android, try the camera's Google Lens mode.
It scans, but nothing opens
If the camera recognises the code but nothing useful opens, the pattern is fine and the problem is the content. The link may be mistyped, the website may be down, or a dynamic code's provider may have deactivated it. See QR code stopped working. Email and SMS codes also need a mail or messages app set up on the phone.
How to test a QR code before printing
- Scan the downloaded file on screen with two phones, ideally one older one.
- Print one test copy at the real size and scan it from the real distance.
- Scan it in the real light: a dim restaurant, a sunny window, a car park at night.
- Check where it opens, not just that it scans.
RelyQr test-scans every design as you make it, and checks codes with a logo at three sizes before you download them.
Questions people also ask
Why can't my iPhone scan a QR code?
Check that Scan QR Codes is on in Settings › Camera, hold the phone steady about a hand's width away, and make sure the whole code, with its margin, is in view. If it still fails, the code itself may be too small or low in contrast.
Why does my QR code work on my phone but not on others?
Newer phones read small, dense and low-contrast codes that older cameras can't. Test on an older phone and print the code bigger or simpler.
How do I scan a QR code from a screenshot?
On iPhone, open the photo and press and hold the code. On Android, open the photo in Google Photos or Google Lens and tap the code.
Do QR codes scan in the dark?
Phones need some light to see the pattern. In dim places, put the code where light reaches it and use a matte, high-contrast print.
Make a QR code that lasts forever
Free static codes with your logo and no watermark. Dynamic codes you can change after printing keep working on every plan.