GS1-128 Barcode Generator – Structured Data for Supply Chain Labels

What Is a GS1-128 Barcode?

GS1-128 (formerly EAN-128 or UCC-128) is an application standard that uses the Code 128 symbology to encode structured supply chain data. What makes GS1-128 unique is its use of Application Identifiers (AIs) – standardised numeric prefixes that define the type and format of the data that follows. This allows a single barcode to carry multiple data fields such as GTIN, batch number, expiry date, net weight and serial number.

GS1-128 always begins with a special Function Code 1 (FNC1) character immediately after the Code 128 start character. This FNC1 tells the scanner that the barcode contains GS1-structured data rather than plain Code 128 text. Without FNC1, the barcode is standard Code 128 and cannot be interpreted by GS1-aware systems.

GS1-128 is mandatory in many industries for shipping labels, pallet labels and logistics documentation. Major retailers like Walmart, Tesco and Carrefour require GS1-128 barcodes on inbound shipments for automated receiving and traceability.

Key Application Identifiers

Application Identifiers are the building blocks of GS1-128. Here are the most commonly used ones:

Variable-length fields are separated by the FNC1 character (rendered as GS, ASCII 29, in transmitted data). Fixed-length fields do not need a separator because the scanner knows exactly how many characters to expect.

Common Use Cases for GS1-128

• • Shipping labels: GS1-128 encodes SSCC, GTIN and shipment data on logistics labels that travel through the entire supply chain from factory to store.
• • Food traceability: Batch numbers and expiry dates encoded in GS1-128 allow rapid product recalls and FIFO inventory management in fresh food supply chains.
• • Pharmaceutical serialisation: Drug packages use GS1-128 (or GS1 DataMatrix) to encode GTIN, serial number, batch and expiry date for compliance with EU FMD and US DSCSA regulations.
• • Pallet identification: SSCC (AI 00) barcodes on pallets enable cross-docking and automated warehouse management without breaking down the pallet.

How to Create a GS1-128 Barcode

1. 1. Open the Barcode Generator and select GS1-128.
2. 2. Enter your data string using Application Identifiers in parentheses, e.g. (01)04012345678901(17)261231(10)ABC123.
3. 3. The generator validates AIs and inserts FNC1 separators automatically. Adjust bar dimensions to meet your label requirements.
4. 4. Download and scan-verify the barcode before production use.

All processing happens in your browser – no data upload, no registration needed, unlimited generation.

GS1-128 vs Standard Code 128

GS1-128 and Code 128 share the same symbology – the bars and spaces are identical. The difference is in the data structure: GS1-128 requires FNC1 as the first character and uses Application Identifiers to give meaning to the encoded data. Standard Code 128 encodes arbitrary text with no predefined structure.

If you only need to encode a simple text string or serial number, plain Code 128 is sufficient. If you need to encode structured supply chain data (GTIN, batch, date, weight) that trading partners can automatically parse, GS1-128 is required.

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