Learn which error correction level to use depending on the size of your QR Code
The error correction of a QR Code allows it to be decoded even if it is partially obscured or slightly damaged thanks to the pattern containing duplicate information (redundancy) of contents.
There are four error correction levels: L, M, Q and H. Each level has its own percentage of damage it can sustain, L being the lowest and H, the highest. Which to use is determined by the actual size of a QR Code when printed.