There are a number of variants of QR code, each with differing characteristics in terms of readability, data density and error correction. Currently the variant offering the greatest data capacity is “40L” (type 40, error correction level L). This utilises a 177 x 177 dot matrix and can be used to represent up to 4,296 alphanumeric characters or 7,089 numeric-only characters.
![Bite-Size Briefings](http://www.barcode-sorted.com/blog/wp-content/uploads/2015/06/bite-size.png)