The smallest element dimension intended for distinction by the barcode scanner. A 1D barcode is comprised of a variety of bars and spaces with varrying widths, the width of the smallest bar or space is the smallest element width or element dimension. Similarly a 2D barcode is an array of contrasting marks, the smallest of those marks along each of two orthogonal axes is the smallest element dimension.

Barcode resolution is often measured in milli-inches. A 5mil 1D code would typically be considered high density, GTIN barcodes are typically printed between 10mil and 39mil. However a 10 mil 2D barcode would be considered high density. This is usually not considered detrimental because 2D barcodes can encode information more densely than 1D barcodes.