GS1 Digital Link

GS1 Digital Link is a standardized method for encoding GS1 identifiers (GTINs) into web-resolvable URIs, conformant with ISO/IEC 18975. It achieves two goals simultaneously:

Offline identification -- identifiers can be extracted from the barcode without internet access
Online information access -- the URI is a functional web address connecting to digital content

The domain is not part of the identifier. This is what makes GS1 Digital Link portable across brands, marketplaces, and compliance registries.

URI structure

https://{domain}/01/{GTIN}/10/{batch}/21/{serial}

Component	Example	Purpose
Domain	`eulabel.eu`	Resolver domain (not part of the identifier)
Primary key (AI 01)	`/01/05601234567890`	GTIN -- the product identifier
Key qualifier (AI 10)	`/10/ABC123`	Batch/lot number
Key qualifier (AI 21)	`/21/1001`	Serial number
Query string	`?linkType=gs1:pip`	Request specific link type

Domain independence

The domain is not part of the product identifier:

https://eulabel.eu/01/05601234567890
https://brand.example/01/05601234567890

Both URIs identify the same product. Identifiers persist independently of any domain, which is essential for ESPR persistence requirements.

Identification granularity

Different levels of identification serve different use cases:

Level	GS1 Encoding	Use Case
Model	GTIN only	Product type identification
Batch	GTIN + lot number	Recall readiness, batch-specific data
Item	GTIN + serial number	Repairs, warranty, individual traceability

Model level

GTIN only — the most common for consumer passports

Batch level

GTIN + lot — recalls, lab results, compliance per batch

Item level

GTIN + serial — repairs, warranty, per-item traceability

Examples

Model level:  https://eulabel.eu/01/09506000164908
Batch level:  https://eulabel.eu/01/09506000164908/10/LOT2025A
Item level:   https://eulabel.eu/01/09506000164908/21/SN00012345

Each level inherits data from above -- everything at the GTIN level applies to all batches and items under it.

Key properties

Globally unique -- no two products share an identifier
Persistent -- identifiers never change throughout the product lifecycle
Web-resolvable -- scan a QR code with any smartphone camera, no app needed
Open standards -- no vendor lock-in, portable across systems
Backward compatible -- same identifiers work in legacy barcode systems

Data carriers

Carrier	Smartphone Support	DPP Suitability
QR Code	Ubiquitous	Primary choice (cited by ESPR)
Data Matrix	Uneven	Good for small/cylindrical products
NFC	Widely implemented	Assessment pending

QR Code with GS1 Digital Link URI syntax is the recommended data carrier for DPP compliance.