Yeah, it's not mandatory. The specification itself recommends a very concrete algorithm though, and one of its criteria is literally the average density [1]. [

Yeah, it's not mandatory. The specification itself recommends a very concrete algorithm though, and one of its criteria is literally the average density [1]. [1] https://github.com/lifthrasiir/qr.js/blob/52f0409a22c5ece6a598f1a81a2ab1d9a3e11458/qr.js#L533-L545 https://github.com/lifthrasiir/qr.js/blob/52f0409a22c5ece6a5...