As the EU implements Digital Product Passports under the ESPR regulation, the question of how to encode product identification becomes critical. The EU has indicated that data carriers must comply with ISO/IEC standards, with GS1 Digital Linkemerging as the recommended approach.
This guide provides a technical deep-dive into GS1 Digital Link—explaining the URL structure, how to encode GTINs and serial numbers, resolver architecture, and practical implementation steps for DPP compliance.
Why GS1 Digital Link for DPP?
- ISO/IEC compliant: Meets EU ESPR data carrier requirements
- Web-native: Works as standard URLs in any browser
- Future-proof: Supported by global supply chain infrastructure
- Multi-purpose: Single code serves consumers, retailers, regulators
What is GS1 Digital Link?
GS1 Digital Link is a standard that converts traditional GS1 identifiers (like barcodes) into web-enabled URLs. It bridges the physical and digital worlds by encoding product identification information directly into a web address.
Traditional Barcode vs. Digital Link
Traditional Barcode (EAN-13)
- • Contains only product identifier
- • Requires database lookup for information
- • Scanner-dependent (needs barcode reader)
- • Single-purpose use
GS1 Digital Link
- • Contains product identifier as URL
- • Links directly to product information
- • Any smartphone can scan (camera app)
- • Multi-purpose (DPP, marketing, retail)
Key Benefits
Universal Scanability
Any smartphone camera can scan the QR code and open the URL—no special app required. This dramatically increases consumer engagement compared to traditional barcodes.
Context-Aware Responses
A resolver can direct different users to different content. Consumers see product info, retailers see inventory data, recyclers see disposal instructions—all from one code.
Backward Compatibility
The GTIN within the URL can be extracted by traditional systems, maintaining compatibility with existing supply chain and retail infrastructure.
URL Structure
GS1 Digital Link URLs follow a specific structure that encodes GS1 identifiers in a web-friendly format. Understanding this structure is essential for DPP implementation.
Basic Structure
Examples
| Use Case | Digital Link URL |
|---|---|
| Product (GTIN only) | https://id.gs1.org/01/09506000134352 |
| Product + Serial | https://id.gs1.org/01/09506000134352/21/ABC123 |
| Product + Batch + Expiry | https://id.gs1.org/01/09506000134352/10/LOT456/17/251231 |
| Custom Domain | https://brand.com/01/09506000134352/21/ABC123 |
Important: URL Encoding
Special characters in serial numbers or batch codes must be URL-encoded. For example, a serial number containing “/” should be encoded as “%2F”. Most QR code generators handle this automatically.
GTIN Encoding
The GTIN (Global Trade Item Number) is the primary identifier used in GS1 Digital Link for products. Understanding GTIN structure is essential for correct implementation.
GTIN Formats
| Format | Digits | Common Name | Use Case |
|---|---|---|---|
| GTIN-8 | 8 | EAN-8 | Small products |
| GTIN-12 | 12 | UPC-A | North America retail |
| GTIN-13 | 13 | EAN-13 | Global retail (most common) |
| GTIN-14 | 14 | ITF-14 | Logistics, cases, pallets |
GTIN-14 Normalization
In GS1 Digital Link, all GTINs should be normalized to 14 digits by adding leading zeros. This ensures consistency across all systems.
Normalization Examples
GTIN Structure
Country/company indicator
Unique to your organization
Your product identifier
Calculated automatically
Application Identifiers
Application Identifiers (AIs) are standardized codes that identify the type of data that follows. They are the building blocks of GS1 Digital Link URLs.
Common AIs for DPP
| AI | Name | Format | DPP Use |
|---|---|---|---|
| 01 | GTIN | 14 digits | Product identification (required) |
| 21 | Serial Number | Up to 20 characters | Unit-level tracking (recommended) |
| 10 | Batch/Lot Number | Up to 20 characters | Batch traceability |
| 11 | Production Date | YYMMDD | Manufacturing date |
| 17 | Expiration Date | YYMMDD | Use-by date |
| 8200 | Extended Packaging URL | URL encoded | Custom DPP destination |
AI Ordering in URLs
AIs in the URL path follow a specific order based on their “key qualifier” relationships:
Resolver Architecture
A resolver is the web service that receives GS1 Digital Link requests and directs users to the appropriate content. It's the “brain” behind context-aware responses.
How Resolvers Work
User scans QR code
Smartphone opens Digital Link URL
Request reaches resolver
Resolver extracts GTIN, serial, and request context
Context-aware routing
Resolver determines appropriate response based on link type
User redirected
DPP page, product info, or other relevant content
Link Types for DPP
| Link Type | GS1 Code | Use Case |
|---|---|---|
| Product Information | gs1:pip | General product details page |
| Digital Product Passport | gs1:sustainabilityInfo | DPP/sustainability data |
| Instructions | gs1:instructions | User manuals, care guides |
| Recycling Info | gs1:recipeInfo | End-of-life guidance |
| Traceability | gs1:traceability | Supply chain data |
Resolver Options
GS1 Resolver (id.gs1.org)
- • Official GS1 service
- • No setup required
- • Limited customization
- • Requires GS1 registration
Custom Resolver (Your Domain)
- • Full branding control
- • Custom analytics
- • Flexible routing logic
- • Requires infrastructure
QR Code Generation
Generating QR codes for GS1 Digital Link URLs requires attention to size, error correction, and print quality. For a detailed comparison of QR codes vs NFC, see ourQR vs NFC guide.
QR Code Requirements
Minimum Size
At least 2cm × 2cm (0.8" × 0.8") for reliable scanning. Larger for complex URLs with serial numbers.
Error Correction Level
Use Level M (15%) for standard applications or Level H (30%) for products prone to damage.
Quiet Zone
Maintain a white border of at least 4 modules around the QR code.
Contrast
High contrast between modules and background (dark on light). Avoid colored QR codes unless tested.
Human-Readable Element
Below the QR code, include a human-readable text element for accessibility and backup:
(01)09506000134352(21)ABC123
Scan for Digital Product Passport
EU ESPR Compliance
The EU ESPR requires data carriers that comply with ISO/IEC standards. GS1 Digital Link encoded in QR codes (ISO/IEC 18004) meets these requirements.
ESPR Data Carrier Requirements
- ISO/IEC 15459 or 18004: GS1 Digital Link in QR format complies ✓
- Machine-readable: URL resolves to structured DPP data ✓
- Unique identifier: GTIN + Serial provides unit-level identification ✓
- Durability: QR code durability depends on print quality and materials ✓
Why GS1 is Preferred
While the ESPR doesn't mandate GS1 specifically, EU guidance documents recommend GS1 Digital Link as the preferred approach because:
- Already used by 2 million+ companies globally for supply chain identification
- Interoperable with existing retail and logistics infrastructure
- Standardized URL structure ensures consistency across EU market
- Resolver architecture enables context-aware content delivery
- Supports both product-level (GTIN) and unit-level (Serial) identification
Implementation Steps
Follow these steps to implement GS1 Digital Link for your Digital Product Passports:
1Obtain GS1 Company Prefix
Register with your local GS1 Member Organization (e.g., GS1 Germany, GS1 US, GS1 UK).
- • Receive unique Company Prefix
- • Access to GS1 standards and tools
- • Annual membership fee applies
2Assign GTINs to Products
Create unique 14-digit GTINs for each product variant.
- • Each SKU/variant needs unique GTIN
- • Calculate check digit correctly
- • Register GTINs in GS1 Registry (optional but recommended)
3Design Serial Number Scheme
For unit-level tracking (recommended for DPP), create a serial number system.
- • Up to 20 alphanumeric characters
- • Must be unique per GTIN
- • Consider sequential vs. random generation
4Set Up Resolver
Configure where Digital Link URLs will redirect to.
- • Use GS1 Resolver (id.gs1.org) or custom domain
- • Configure link types (DPP, product info, etc.)
- • Set up redirects to your DPP pages
5Generate and Print QR Codes
Create QR codes encoding your Digital Link URLs.
- • Use ISO/IEC 18004 compliant generator
- • Test scanning on multiple devices
- • Verify redirect to correct DPP
6Create DPP Content
Populate your DPP pages with required information.
- • Include all required data fields
- • Structure data for machine readability
- • Design for consumer accessibility
Frequently Asked Questions
What is GS1 Digital Link?
GS1 Digital Link is a standard that transforms traditional barcodes into web-enabled identifiers. It creates URLs that contain GS1 identification keys (like GTINs) in a web-friendly format, allowing a single QR code to link to multiple types of content including product information, Digital Product Passports, manuals, and marketing materials.
Is GS1 Digital Link required for EU Digital Product Passports?
While the EU ESPR does not mandate GS1 Digital Link specifically, it requires data carriers (QR codes) that comply with ISO/IEC standards. GS1 Digital Link is the recommended approach as it provides a standardized, future-proof URL structure that is explicitly mentioned in EU guidance documents.
What is the GS1 Digital Link URL structure?
The basic GS1 Digital Link structure is: https://[domain]/[primaryKey]/[value]. For product identification, this typically looks like: https://id.gs1.org/01/09506000134352 where 01 is the Application Identifier for GTIN and the number is the 14-digit GTIN. Additional identifiers like serial numbers can be appended.
Do I need a GS1 membership to use Digital Link?
Yes, you need a GS1 Company Prefix to generate valid GTINs. GS1 membership is obtained through your local GS1 Member Organization. Membership provides a unique Company Prefix, access to GS1 standards, and often includes resolver services and technical support.
Can I use my own domain for GS1 Digital Link?
Yes, you can use your own domain (e.g., https://brand.com/01/09506000134352) instead of id.gs1.org. This is called a custom resolver and requires proper DNS and resolver configuration. Many brands prefer this for branding purposes while maintaining GS1 standard compliance.
Conclusion
GS1 Digital Link provides a standardized, future-proof foundation for Digital Product Passport implementation. By encoding GTINs and serial numbers in web URLs, it enables seamless scanning, context-aware content delivery, and interoperability with existing supply chain systems.
While GS1 membership and resolver setup require initial investment, the long-term benefits of standardization—regulatory compliance, consumer accessibility, and supply chain integration—make it the recommended approach for EU DPP compliance.
Key Takeaways
- GS1 Digital Link is the recommended standard for DPP data carriers
- Use GTIN + Serial Number (AIs 01 + 21) for unit-level identification
- Configure a resolver for context-aware content delivery
- Generate ISO/IEC 18004 compliant QR codes with proper sizing
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