1 The size of QR modules in pixels specifies how many pixels each module (i.e., the smallest individual unit or square within the QR code matrix) should occupy. For example, if the size is set to 10, each module of the QR code will be 10 pixels by 10 pixels in size. The overall size of the QR code image (in pixels) is influenced by both the number of modules and the size of each module. The number of modules in a QR code is determined by the amount of data you are encoding and the version of the QR code.
2 QR codes use error correction to ensure that the encoded information can still be read accurately even if the code is partially damaged or distorted. There are four error correction levels in QR codes: Low (about 7% or fewer errors can be corrected); Medium (about 15% or fewer errors can be corrected); Quartile (about 25% or fewer errors can be corrected); High (about 30% or fewer errors can be corrected). The error correction level determines the amount of redundancy added to the QR code. Higher error correction levels add more redundancy but also increase the amount of data that needs to be stored, resulting in a larger QR code. When choosing the error correction level, you need to consider factors such as the likelihood of the QR code being damaged or distorted and the available space for the QR code. For most general use cases, the default choice is often L or M, balancing error correction with code size. However, in environments where the QR code may be subject to more wear and tear, a higher error correction level (such as Q or H) might be more suitable.