QR Codes Done Right: Generation, Testing, and Common Mistakes
QR codes seem foolproof until you print 500 event badges and discover that the code is too small to scan or the contrast is too low. Here is what I have learned about generating QR codes that work every time.
Size and Scanning Distance
A QR code should be at least 2cm x 2cm for close-range scanning. For codes printed on posters viewed from 1-2 meters away, aim for 5cm or larger. The general rule: scanning distance divided by 10 equals minimum QR code width.
Common Mistakes
- Too much data: More data = denser QR code = harder to scan. Keep URLs short (use a URL shortener if needed)
- Low contrast: Dark QR on light background works. Light QR on dark background often fails. Avoid colored QR codes unless you test extensively
- No quiet zone: QR codes need a white margin (4 modules wide) around all sides. Designs that crowd the code will break scanning
- Printing too small: Test-scan your printed QR code from the expected distance before mass printing. Phone cameras vary in quality
Testing Your QR Codes
Always test with multiple devices: iPhone, Android, old and new models. What scans on an iPhone 15 may fail on a budget Android from 2019. Our QR Code Generator creates standard-compliant codes at configurable sizes. Download as PNG at 256x256 pixels or larger for print use.
This article was written by UnTrackedTools founder Alex Chen, based on real event planning and marketing material experience.