GS1 Barcodes: Types, Keys and Data Explained

Identification Keys

• GTIN: the Global Trade Item Number of a trade item, such as a product sold in a store.
• SSCC: the Serial Shipping Container Code of a logistic unit, such as a pallet.
• GLN: the Global Location Number of a physical location.

Who Issues the Numbers

GS1 Member Organizations license GS1 Company Prefixes, from which companies build their GTINs, SSCCs and other keys; some also sell individual GTINs, which are single product numbers and give no prefix for SSCCs. A barcode generator, this one included, draws a barcode for a number but does not issue it.

Retail Checkout

Products scanned at a store checkout carry EAN-13 or UPC-A, or EAN-8 and UPC-E on small packages. These hold only the GTIN.

UPC barcode generator UPC-A and UPC-E.

EAN-13 barcode generator EAN-13 and EAN-8.

Distribution and Logistics

Cartons carry ITF-14 or GS1-128, and pallet labels carry the SSCC in GS1-128. GS1-128 adds data such as batch numbers, dates and counts with Application Identifiers.

ITF-14 barcode generator the carton barcode with bearer bars.

GS1-128 barcode generator element strings checked with GS1's engine.

SSCC barcode generator the pallet label number in a GS1-128.

2D Barcodes

GS1 DataMatrix carries element strings, and a QR Code or Data Matrix can carry the same data as a GS1 Digital Link URI. GS1 QR Code, the element string form of QR Code, is read by the scanner on this site but not generated.

GS1 DataMatrix generator GS1 data in a small 2D code.

GS1 Digital Link generator your GTIN in a web address, as a QR Code or Data Matrix.

Application Identifiers

The GS1 Barcode Syntax Dictionary of January 27, 2026 lists 541 AIs, from (00) for the SSCC to (99) for company internal information. Each has a defined format, and some are only valid together with others, such as a batch number with a GTIN.

FNC1 and Separators

GS1-128, GS1 DataMatrix and GS1 QR Code start their data with the FNC1 character, which tells the scanner that element strings follow; the scanner does not pass this first FNC1 on. Inside the data, a value without a predefined length is followed by a separator when another AI comes next.

GS1 Digital Link

A GS1 Digital Link URI writes the keys and AIs as a web address, such as https://id.gs1.org/01/09506000134352/10/LOT42, so a QR Code can also open a web page. It is encoded as plain text without FNC1, and software recognizes it by checking the URI against GS1's syntax (GS1 System Architecture, section 5.2.3).

The Encoded Message

Encoded, the message is FNC1 followed by 01095060001343521727123110LOT42. The brackets are not encoded, and because (01) and (17) have predefined lengths, no separator is needed before (10).

Steps to Your First GS1 Barcode

1. Contact your GS1 Member Organization, such as GS1 US in the United States.
2. License a GS1 Company Prefix, or buy individual GTINs where your organization sells them and you only need product numbers.
3. Assign a GTIN to each product, and an SSCC to each logistic unit you ship; SSCCs need a GS1 Company Prefix.
4. Make the barcodes here and scan a test print before printing labels.

Check the Data

Paste element strings, raw data, scanner output or a GS1 Digital Link URI into Check GS1 data, under the Application Identifiers of the GS1-128 or GS1 DataMatrix generator. It names the AI and the rule when something is wrong.

Check the Print

A barcode verifier grades a printed symbol, and GS1 sets the minimum grade for each application. This site cannot grade print quality; it can only confirm that a print scans and holds the right data.