Size: How Big Should Your QR Code Be?
The most common reason QR codes fail is that they are too small. A tiny QR code on a poster across the room is impossible to scan. Use these guidelines:
- 1.The 10:1 rule. The QR code should be at least 1/10th of the expected scanning distance. If someone will scan from 1 meter away, the QR code needs to be at least 10cm wide. From 30cm (a table), at least 3cm.
- 2.Business cards: Minimum 2cm x 2cm. Ideally 2.5cm. See our business card QR code guide for placement tips.
- 3.Table tents and stickers: At least 3cm x 3cm. Restaurant menu QR codes should be easy to scan even in dim lighting.
- 4.Posters and billboards: Scale up significantly. A poster on a wall should have a QR code at least 15-20cm wide. Billboards need even larger codes.
- 5.Digital screens: On websites and presentations, make sure the QR code is at least 200x200 pixels. On phones, it needs to be large enough for another phone's camera to read it.
Contrast and Color: What Works and What Fails
Dark on light is the rule
QR code scanners look for dark modules on a light background. Black on white is the most reliable combination. You can use brand colors, but maintain at least 70% contrast between the foreground and background.
Never invert colors
Light foreground on dark background (white QR code on black background) fails on many scanners. If your design has a dark background, place the QR code inside a white box with padding.
Avoid gradients and patterns
The background behind the QR code must be solid and uniform. Gradients, textures, and photographic backgrounds make scanning unreliable. If your design has a busy background, add a white rectangle behind the QR code.
Placement: Where to Put Your QR Code
Even a perfectly designed QR code is useless if people cannot reach it with their phone camera. Follow these placement guidelines:
- ✓ Eye to chest level. On walls and signs, place QR codes between 1 and 1.5 meters from the ground. Above head height or below knee level makes scanning awkward.
- ✓ Flat surfaces. QR codes on curved surfaces (bottles, pillars) distort and become harder to scan. If you must use a curved surface, increase the QR code size to compensate.
- ✓ Well-lit areas. Phone cameras need light to read QR codes. Avoid placing them in dark corners, under tables, or in areas with heavy shadows.
- ✓ Away from reflective materials. Glossy lamination, glass, and metallic surfaces create glare that interferes with scanning. Use matte finishes when possible.
- ✓ Add a call to action. Always include text like "Scan for Menu," "Scan to Save Contact," or "Scan for Details." People need to know what to expect before they point their camera.
Error Correction: Building in Redundancy
QR codes have built-in error correction that allows them to remain scannable even when partially damaged. There are four levels:
Level L (Low) - 7% Recovery
The code can withstand 7% damage. Produces the simplest, smallest QR code. Best for digital use where the code won't get damaged — websites, emails, and app screens.
Level M (Medium) - 15% Recovery
The default for most generators. Good balance between density and reliability. Works for most print applications — flyers, brochures, and product packaging.
Level Q (Quartile) - 25% Recovery
Better for outdoor or high-wear environments where the QR code might get scratched, stained, or partially covered. Use for outdoor signs, vehicle wraps, and stickers in high-traffic areas.
Level H (High) - 30% Recovery
Maximum redundancy. Required if you want to overlay a logo on the QR code — the logo covers some modules, and error correction compensates. The trade-off is a denser, more complex code that needs to be printed larger.
Testing Checklist Before You Print
Never skip testing. Print one sample and verify everything works before doing a bulk run. Here is your checklist:
- ✓ Scan with an iPhone. Use the built-in camera app (no third-party QR app).
- ✓ Scan with an Android phone. Use the default camera or Google Lens.
- ✓ Scan in bright light. Test in normal indoor lighting.
- ✓ Scan in dim light. Test in the actual environment — a dimly lit restaurant, a dark trade show booth, etc.
- ✓ Scan from the expected distance. Stand as far away as a real person would and try to scan.
- ✓ Verify the destination. Make sure the URL loads correctly, the PDF opens, or the vCard saves properly.
- ✓ Check the printed quality. Make sure the printer did not blur or distort the QR code modules. Inkjet printers at low resolution can make QR codes unscannable.