Code 128 Barcodes: High-Density Character Sets & Global Logistics

The Versatile Workhorse of Global Supply Chains

While consumer retail packaging utilizes fixed-length numeric codes (UPC-A and EAN-13), industrial shipping, carton routing, medical serial tracking, and inventory management rely on **Code 128**.

Introduced in 1981, Code 128 is a high-density, variable-length linear symbology capable of encoding all 128 ASCII characters (uppercase letters, lowercase letters, numbers, punctuation, and control codes).

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The Three Code Subsets (A, B, C)

Code 128 achieves its industry-leading density by dynamically switching between three distinct character sets:

• **Code 128A:** Encodes uppercase letters, digits, punctuation, and ASCII control codes (NUL, STX, CR, LF).
• **Code 128B:** Encodes uppercase and lowercase letters, digits, and all standard ASCII punctuation symbols.
• **Code 128C:** Specially optimized for pairs of digits. It compresses two numeric digits into a single barcode character, halving the physical horizontal length required for numeric serials and tracking numbers.

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GS1-128 & Parcel Shipping Labels

The global logistics standard **GS1-128** (formerly known as UCC/EAN-128) builds upon Code 128 by introducing Application Identifiers (AIs). These standardized numeric prefixes allow automated sorting conveyers to instantly decipher:

• `(00)`: Serial Shipping Container Code (SSCC-18)
• `(01)`: Global Trade Item Number (GTIN)
• `(10)`: Batch / Lot Number
• `(17)`: Expiration Date

Our Barcode Studio automatically generates verified Code 128 barcodes with quiet margins and optional human-readable text ready for label printing.