A QR Code (Quick Response Code) is a two-dimensional barcode invented in 1994 by Denso Wave, originally designed to track automotive parts during manufacturing. Unlike traditional 1D barcodes that store data only horizontally, a QR code encodes information in both horizontal and vertical directions using a square grid of black and white modules. A standard QR Code can store up to 7,089 numeric characters or 4,296 alphanumeric characters—far more than any 1D barcode—making it ideal for URLs, contact information, product serialization, and mobile ticketing.

QR codes incorporate three distinctive square finder patterns in their corners that allow scanners and smartphone cameras to detect the code's position, size, and orientation regardless of the scanning angle. They also include built-in error correction (levels L, M, Q, and H) that allows the code to remain scannable even if up to 30% of the symbol is damaged or obscured. This robustness makes QR codes widely used in logistics, healthcare wristbands, event ticketing, and marketing campaigns. For example, a Zebra TC72 mobile computer running a warehouse management system can scan a QR code on a shipping pallet to instantly retrieve full shipment details, lot numbers, and handling instructions.

In industrial AIDC applications, QR codes are often printed with direct thermal or thermal transfer label printers like the Zebra ZD621 and read by area-imaging scanners such as the Honeywell DS3678. When choosing between QR code and other 2D symbologies like Data Matrix, consider that QR is optimized for consumer-facing applications and larger data payloads, while Data Matrix excels in high-density marking of small parts. Both are part of the ISO/IEC 18004 and 16022 standards respectively.