Why two QR Codes with the same URL can look different?
Every QR Code Generator uses different algorithms and also different encodings (Numeric, Alphanumeric, Byte Mode, Kanji Mode, ECI Mode) when creating a QR Code. Therefore, it is possible that different looking QR Codes can have the same URL or text information encoded. Another possibility are different error correction levels (L, M, Q or H). The higher the error correction is set the bigger the QR Code gets.