A QR code can be as small as 1 cm by 1 cm (10 mm x 10 mm or 0.4 inches x 0.4 inches) under ideal conditions, especially close-range scanning. However, a more practical minimum size is around 2 cm by 2 cm (0.8 inches x 0.8 inches) to ensure reliable scanning with most smartphones. The exact minimum size depends on factors such as scanning distance, data density, QR code version, and error correction level. Smaller QR codes hold less data and require higher contrast and careful printing to be readable.
Minimum Size Details
- 1 cm x 1 cm is the theoretical minimum size, suitable mostly for simple QR codes scanned from very close.
- 2 cm x 2 cm is a recommended minimum for general usability, especially on business cards or product packaging.
- QR code modules (the black and white squares) should be at least 0.25 mm in size.
- The smallest standard QR code (version 1) consists of 21 x 21 modules.
- Micro QR codes are smaller but less widely supported and may require specialized apps.
Factors Influencing QR Code Size
- Scanning distance: The farther the scanning distance, the larger the QR code needs to be.
- Data capacity: More data requires a larger QR code.
- Error correction: Higher correction levels require more space.
- Print quality and material: High resolution and good contrast help smaller codes scan better.
In summary, while QR codes can be made very small, practical use usually calls for a size starting at about 2 cm square for reliable scanning in typical scenarios.
