Why QR Codes Always Have Three Corner Squares

QR codes owe their instant readability to three large corner squares, known as finder patterns, which help cameras identify and orient the code in milliseconds. Developed by Japan's Denso Wave in 1994 for managing automobile parts, the format employs Reed-Solomon error correction, so up to 30 percent of a code can be damaged or hidden and it still scans. The system's limitations—missing quiet zones, glare, and overcrowded data—can break decoding.