Code 128

Code 128 is a high-density linear (1D) barcode that can encode all 128 ASCII characters, making it one of the most versatile barcodes for alphanumeric data. It has no fixed length, so it adapts to short or long strings.

How it works

It uses three interchangeable code sets (A, B and C) that switch between letters, control characters and pairs of digits mid-symbol for maximum compactness, and a mandatory modulo-103 checksum guards against misreads.

Where it's used

Widely used on shipping and logistics labels, product packaging, and internal inventory or asset tags where a compact, reliable alphanumeric code is needed.