Barcodes come in a variety of formats. Most barcodes in use today are linear, or 1D barcodes. Options available include Interleaved 2 of 5 Code for continuous numeric data. Code 39 is an alphanumeric barcode. Code 128 has a number of advanced features and requires a check digit.

2D barcodes appear as a series of black squares on a white background. They are becoming more common, but are very specific in their application.

3D Barcodes Advancement in barcode reader technology allows the camera in a mobile phone to act as a reader.