The key QR code sizing terms are module, quiet zone, error correction level, DPI, Version, SVG, PNG, dynamic QR code, static QR code, and scanning distance.
- Module
- A module is the smallest black or white square unit in a QR code pattern.
- Quiet zone
- The quiet zone is the blank white border around a QR code, and ISO/IEC 18004 requires it to be at least 4 modules wide.
- Error correction level
- An error correction level is the L, M, Q, or H setting that defines how much of the QR code can be damaged and still decode.
- DPI
- DPI means dots per inch, the print resolution measurement used to determine whether the QR code edges will reproduce sharply.
- Version
- A QR code Version is the grid complexity level from 1 to 40; Version 1 has 21 x 21 modules and each higher Version adds 4 modules per side.
- SVG
- SVG is a vector format that scales without pixelation and is preferred for print QR codes.
- PNG
- PNG is a raster image format that works for digital QR codes when exported at sufficient pixel size.
- Dynamic QR code
- A dynamic QR code stores a short redirect URL, which can reduce module density and allow the destination to be changed after printing.
- Static QR code
- A static QR code stores the final data permanently inside the code, so long URLs increase module density.
- Scanning distance
- Scanning distance is the physical gap between the user's camera and the QR code surface.