Introduction
GS1 Digital Link is a standard that enables the connection between physical products and their digital identities by encoding GS1 identifiers into web-enabled URIs. This allows any product with a GS1 Digital Link barcode to provide direct access to product information, traceability data, and digital services through a simple web link.
While the GS1 Digital Link standard encompasses multiple layers (including Resolution, Data Services, and Applications), our focus is on the foundational URI Syntax Layer. This layer defines the standardized structure for encoding GS1 identifiers and attributes in web URIs, ensuring consistent interpretation across the supply chain. Datalogic’s scanner parameters, such as “Check GS1 Format” and “GS1 2D Conversion”, operate primarily at this layer, validating URI structure and managing format conversions.
Understanding GS1 Digital Link Content
Global Trade Item Numbers (GTIN)
At the heart of GS1 Digital Link is the GTIN (Global Trade Item Number), which uniquely identifies trade items worldwide. GTINs come in several formats you might recognize:
- GTIN-13 (formerly EAN-13): The most common format in Europe, like “5901234123457”
- GTIN-12 (formerly UPC-A): Common in North America, like “123456789012”
- GTIN-8 (formerly EAN-8): Used for smaller packages, like “40170725”.
- GTIN-14: The standard format used in GS1 Digital Link
In GS1 Digital Link, all these formats are standardized to GTIN-14 by adding leading zeros when needed. This standardization ensures consistent product identification across different systems and regions.
Application Identifiers (AIs)
Application Identifiers are standardized two-to-four-digit codes that define what kind of data follows them. Think of them as prefixes that give meaning to the numbers that follow. For example, when you see “01” in a GS1 Digital Link URI, you know the next 14 digits represent a GTIN.
Here are the most common AIs used in retail:
| AI | Definition | Format | Example |
|---|---|---|---|
| 01 | GTIN | n14 | (01)09506000134376 |
| 10 | Batch/Lot Number | X…20 | (10)ABC123 |
| 11 | Production Date | n6 | (11)211225 |
| 15 | Best Before Date | n6 | (15)230615 |
| 17 | Expiration Date | n6 | (17)240531 |
| 21 | Serial Number | X…20 | (21)12345678 |
| 310n* | Net Weight (kg) | n6 | (3103)000195 |
| 392n* | Price | n…15 | (3922)0299 |
*n indicates decimal point position
URI Structure Components
A GS1 Digital Link URI follows this fundamental structure:
-
The URI structure begins with the standard web protocol (https://) followed by a domain name. This could be a brand’s own domain or a GS1-provided resolver like id.gs1.org.
For example:https://id.gs1.org -
The GS1 Primary Identification Key comes next and is crucial - it’s typically your product’s GTIN prefixed with “01” (the AI for GTIN). For example, if your product has an EAN-13 barcode “9312345678907”, in the URI it would appear as:
/01/09312345678907, and its GS1 Digital Link syntax would look like “https://id.gs1.org/01/09312345678907”. -
Key Qualifiers add more specific identification. They follow a sequence that increases in specificity from left to right. For instance, after your GTIN, you might add a batch number (AI “10”, like “
/10/ABC123”) followed by a serial number (AI “21”, like “/21/456789A”). Each qualifier helps narrow down the identification from product class to specific instance. The resulting GS1 Digital Link syntax would look like: "https://id.gs1.org/01/09312345678907/10/ABC123/21/456789A". -
Data Attributes come last and provide additional information like expiry dates, weights, or prices. Unlike key qualifiers, these appear as query string parameters in the URL, and their order doesn’t matter. A complete URI might include multiple attributes, giving detailed information about that specific product instance. For example:
- Expiry date (AI “17”):
?17=240531 - Net weight (AI “310n”):
&3103=000195
The resulting GS1 Digital Link syntax would look like: "https://id.gs1.org/01/09312345678907/10/ABC123/21/456789A?17=240531&3103=000195 ".
For more information see also: