DropMyPageWhen a QR code won't scan, the problem is almost always one of a few things: too little contrast, too small for the distance, no white border around it, or the link inside has stopped working. Work through the fixes below in order. Most codes start scanning after the first three.
1. Use dark on light, with strong contrast
Phone cameras look for dark squares on a light background. Black on white is safest. Coloured codes can work, but keep the foreground dark (navy, dark green, dark brown) and the background very light. Never invert it (light code on a dark background): many scanners can't read that.
2. Make it big enough for the distance
A simple rule of thumb: the code should be at least one tenth of the scanning distance wide.
| Where it's scanned from | Minimum width |
|---|---|
| Table card or menu (30 cm) | 3 cm |
| Shop counter (1 m) | 10 cm |
| Poster on a wall (2 m) | 20 cm |
| Window or banner (5 m) | 50 cm |
When in doubt, go bigger and test from where people will actually stand.
3. Keep the white border (quiet zone)
QR codes need empty space around them, about four squares wide, so the camera can find the edges. Designs that crop the code tight, or place it against a busy photo, often fail. Add a white margin around the code.
4. Don't put too much inside it
The more text a QR code holds, the denser and harder to scan it gets. A short link scans far better than a long one or a block of text. Instead of putting a whole page into the code, put a short link to the page in it, for example by turning your PDF or HTML page into a link with PDF to QR code.
5. Pick the right error correction
QR codes can repair damage using "error correction". Higher levels survive scratches and smudges but make the code denser. Medium suits most uses. Use High for codes that will get dirty or worn, such as outdoor signs, and make them a bit larger to compensate. You can choose the level in our free QR code generator.
6. Print it sharp
Blurry edges confuse scanners. Export the code as a large PNG (1024 px or more) or SVG, never a screenshot, and don't stretch it unevenly. Avoid glossy laminate that reflects light straight at the camera.
7. Check the surface and lighting
Codes on curved bottles, crumpled paper or behind reflective glass are harder to scan. Flat, matte and well-lit works best.
8. Make sure the link still works
Sometimes the code scans fine but the page behind it is gone. Free links on many services expire, and websites change addresses. Open the link yourself. If the code is printed and must keep working for months, use a link that doesn't expire, or a service that lets you update the page behind the same link.
9. Test on two phones before printing many
Test with an iPhone and an Android phone, using the built-in camera app, from the real distance. Print one copy first. It costs far less than reprinting a hundred menus.
Quick checklist
- Dark code on a light background
- At least 1/10 of the scanning distance wide
- White border around it
- Short link inside, not long text
- Printed from a large, sharp image
- Link opens, and won't expire too soon
- Tested on two phones
FAQ
Why does my QR code scan on one phone but not another?
Older phones and some third-party scanner apps are less forgiving. Improve contrast and size, and it will usually work everywhere.
Can I add a logo in the middle?
Yes, if it covers only a small part of the code and you use High error correction. Always test afterwards.
Do QR codes expire?
The code itself never expires. What can stop working is the link inside it. That's why the page behind the code matters as much as the code.
What's the easiest way to make one?
Use a free QR code generator for links, WiFi or contact details. For a whole menu or flyer, turn it into a link first and put that link in the code.