QR Code Best Practices: Size, Contrast, and Print Tips
Make QR codes that always scan. Learn the right size, quiet zone, contrast and file formats for print and screen, plus the mistakes that break codes.
A QR code that does not scan is worse than no code at all — it advertises effort while delivering frustration. The good news: reliable scanning comes down to a handful of rules about size, spacing, contrast and file format. Follow these and your codes will just work.
Size: match it to scanning distance
The classic guideline is a 10:1 ratio of distance to size. If people scan from 30 cm away, the code should be about 3 cm wide. A billboard scanned from 10 metres needs a code roughly a metre across. When in doubt, go bigger — an oversized code still scans, an undersized one does not.
Quiet zone: give it breathing room
Every QR code needs an empty margin — the "quiet zone" — around all four sides so scanners can find its edges. Aim for a clear border at least four modules wide, and never let text or graphics crowd right up against the pattern.
Contrast: dark on light
- Keep strong contrast between the foreground and background.
- Dark code on a light background is the most reliable combination.
- Avoid light codes on dark backgrounds — many scanners struggle with inverted codes.
- If you use brand colors, test with several phones before printing.
A good editor warns you when a color pairing may be hard to scan. Heed the warning — a slightly less trendy code that always scans beats a beautiful one that fails.
File format: vector for print
Use SVG or PDF for anything printed. These are vector formats, so the code stays perfectly sharp at any size, from a business card to a banner. Use PNG for screens and digital placements. Avoid scaling up a small JPG or PNG, which introduces blur that can break scanning.
Adding a logo without breaking the code
A center logo is fine as long as error correction is high enough to compensate. Keep the logo under about 20–25% of the code area and leave the three corner squares fully visible — they are how scanners orient the code.
Common reasons codes fail
- Printed too small for the scanning distance.
- No quiet zone, or graphics touching the pattern.
- Low contrast or inverted colors.
- Blurry raster image scaled beyond its resolution.
- A logo so large it covers essential data or a corner marker.
Keep these in mind and every code you ship will scan on the first try. Put them into practice with the free generator.