从文本、URL、电子邮件地址、WiFi凭据等生成二维码。
QR (Quick Response) codes are two-dimensional barcodes that store information in a matrix of black and white squares. Created in 1994 by Denso Wave for tracking automotive parts, QR codes are now ubiquitous for sharing URLs, contact information, and other data. They can store up to 4,296 alphanumeric characters.
QR codes encode data in patterns of modules (black/white squares). They include error correction using Reed-Solomon codes, allowing partial recovery if damaged. The three large squares in corners help scanners detect orientation. Different versions (1-40) offer varying capacities.
Maximum capacity is 4,296 alphanumeric characters or 7,089 numeric digits. However, more data means more modules and harder scanning. Keep content short for best reliability.
Error correction allows QR codes to remain readable even when partially obscured or damaged. Levels range from L (7% recovery) to H (30% recovery). Higher correction means larger codes.