Code 128 Barcode Generator

Code 128 is a high-density linear barcode that encodes all 128 ASCII characters including numbers, letters, and symbols. It has three subsets: A (uppercase + control), B (uppercase + lowercase), C (numeric pairs). It is widely used in shipping and packaging.

Code 128 has no fixed maximum length, but practical limits depend on scanner capability and print width. Typical maximum is 20-30 characters for reliable scanning. Longer data increases barcode width. Use subset C for numeric-only data to reduce width by half.

Code 128 is more compact (higher density), encodes all ASCII characters, and includes a checksum. Code 39 is simpler, self-checking, but less dense and limited to 43 characters. Code 128 is preferred for shipping labels; Code 39 for industrial applications.

GS1-128 (formerly UCC/EAN-128) uses Code 128 with GS1 Application Identifiers. Start with FNC1 character, then AI code: (01) for GTIN, (10) for batch, (17) for expiry date. The generator supports GS1-128 format with proper AI formatting.

Minimum bar width (X dimension): 0.25 mm for close-range scanning, 0.5 mm for retail. Height: at least 15% of width or 6.35 mm minimum. Quiet zones: 10X on each side. The generator produces print-ready barcodes at specified dimensions.