QR codes that work in testing can fail in the real world due to printing, lighting, or camera quality issues. Following best practices ensures reliable scanning across conditions.
Size and Distance
The scanning distance is roughly 10× the QR code width. A 1-inch code scans at about 10 inches. For posters viewed from 6 feet, the code should be at least 7 inches. When in doubt, larger is better—but extremely large codes need proportionally farther distance.
Contrast and Colors
Maximum contrast (black on white) is most reliable. If using colors, ensure dark modules are truly dark and light areas are truly light. Avoid red data modules—many cameras have weak red sensitivity. Test colored codes on multiple devices before deployment.
Quiet Zone
Maintain a quiet zone (blank margin) around the code—at least 4 modules wide, preferably more. This helps scanners distinguish the code from surrounding content. Don't place codes too close to edges or other graphics.
Content Considerations
Use URL shorteners for long URLs to keep codes simple. Short URLs mean smaller codes that scan more reliably. Track scans with analytics parameters. Consider what happens if the destination changes—use redirect URLs you control.