Micro QR Code Specifications: M1 to M4 Formats for Ultra-Small Components

1. Why Standard QR Codes Cannot Fit Small Parts

A standard Version 1 QR code requires a 21x21 module grid plus a 4-module quiet zone, totaling 29x29 modules. When marking tiny printed circuit boards (PCBs), pharmaceutical vials, or watch movements, this spatial footprint is prohibitive.

2. Micro QR Architecture (ISO/IEC 18004 Annex K)

Micro QR codes conserve massive physical space through three architectural changes: 1. Single Finder Pattern: Contains only one position detection marker located at the top-left corner (instead of three). 2. Reduced Quiet Zone: Requires a quiet zone of only 2 modules instead of 4. 3. Compact Matrix Sizes: * M1 (11x11 modules): Stores up to 5 numeric digits. * M2 (13x13 modules): Stores up to 10 numeric digits or 6 alphanumeric characters. * M3 (15x15 modules): Stores up to 21 numeric digits or 15 bytes. * M4 (17x17 modules): Stores up to 35 numeric digits or 21 alphanumeric characters with Reed-Solomon error correction.