QR Code Printing Size/ Error Correction Levels contd.

The data shown below is - QR Code Size Specification. (Source: QR Stuff, 2011)
 Modules: Number of rows and columns of little black squares in the QR code image.
 Characters: Approximate number of characters that would normally fit into a QR code with that many modules using binary data encoding (most do) and Level L error correction.
 Scan Distance: The distance the camera is being held away from the printed QR code.

This is also one of the reasons why a QR code containing the same data will look different depending on which QR code generator you use – it depends on the error correction level being used by that particular website. Even though there is a single ISO standard for QR codes, there are variables within the ISO standard (error correction level being one of them) that will result in a different looking QR code image based on how that particular QR code creation website sets these variables.
As the data load gets higher, the modules (cells) get smaller hence a denser QR Code image (See below).