Format Information

Format information is a 15-bit data area placed around the finder patterns of a QR code. It stores the error correction level (L/M/Q/H) and mask pattern number (0-7) in use. Scanners read this information first to determine the data decoding method.

The format information itself is error-corrected using BCH codes, remaining readable even when partially damaged. The same information is redundantly placed in two locations, allowing recovery from one if the other is dirty. It is a critical mechanism supporting QR code robustness.