GS1 Digital Link and JSON-LD: Technical Standards Enabling the EU Digital Product Passport (DPP)

Executive Summary

European Commission Mandate M/594 tasked the CEN/CENELEC Joint Technical Committee JTC 24 with developing eight harmonised standards for Digital Product Passports (DPP). The standards establish consistent rules governing physical data carriers, registration protocols and cryptographic security frameworks.

Key framework references include EU Mandate M/594, prEN 18246 (data authentication), prEN 18220 (data carriers), W3C Verifiable Credentials and GS1 Digital Link. These horizontal cross-sector specifications facilitate interoperable product passports across all commodity categories. All eight standards reached final draft status in March 2026. Official publication is scheduled for Q2–Q4 2026, followed by national transposition within EU Member States.

Crucially, the EU Digital Product Passport is neither a static PDF document nor a simple redirect link hosted behind consumer-facing QR codes. It defines a standards-compliant, machine-readable, interoperable data payload accessible via a single physical identifier. Authorised stakeholders – consumers, customs authorities, recycling operators, market surveillance bodies and automated digital systems – may retrieve structured product data through this identifier. The technical foundation of the DPP ecosystem rests on two primary specifications: GS1 Digital Link (identification and routing layer) and JSON-LD (data payload and semantic interoperability layer). This white paper provides a technical breakdown of both standards, outlines the full suite of JTC 24 specifications and defines practical implementation requirements for market operators.

1. GS1 Digital Link: Universal Unique Product Identification

Standard Overview

GS1 Digital Link is formalised within GS1 General Specifications Version 23 (2024) and published as ISO/IEC 18975:2024 Automatic identification and data capture techniques — GS1 Digital Link. The specification carries regulatory recognition under EU legislation, maintained via open multi-stakeholder consensus independent of single commercial entity control.

The standard addresses a critical industry limitation: enabling one barcode or RFID tag to support parallel use cases, including retail point-of-sale scanning, consumer information retrieval, regulatory compliance verification and end-of-life sorting. GS1 Application Identifiers (AIs) are encoded as path segments within resolvable web Uniform Resource Identifiers (URIs).

Reference URI structure:

https://id.brand.com/01/09506000134352/21/SERIAL-2026-K78/10/BATCH-Q2-YARN27

URI Component Mapping Table

URI Segment	GS1 Application Identifier (AI)	Description	Example Value	Mandatory
`https://id.brand.com/`	—	Brand-controlled resolver domain with SSL encryption and validated DNS configuration	Custom enterprise domain	Yes
`01/09506000134352`	AI 01	GTIN‑14 Global Trade Item Number	Unique base product identifier	Yes
`21/SERIAL-2026-K78`	AI 21	Item-level serial number	Unique identifier for each physical unit	Yes
`10/BATCH-Q2-YARN27`	AI 10	Production batch/lot identifier	Traceability reference for manufacturing batches	Recommended
`?17=260531` (query parameter)	AI 17	Expiry date (YYMMDD format)	Product validity metadata	Optional

DPP Implementation Benefits

Conventional identification architectures frequently operate in silos: separate GTIN barcodes for retail, standalone QR codes for consumers and dedicated web endpoints for regulators. Multiple identifiers for a single product fragment traceability workflows, increase authentication overhead and conflict with the ESPR requirement for a single trusted data source.

GS1 Digital Link delivers a unified URI usable across all stakeholder groups. The standardised resolution workflow is outlined below:

QR Code / Mobile Device / NFC / RFID Reader
        ↓
Brand resolver service: https://id.brand.com/01/GTIN/21/serialnumber
        ↓
Content negotiation via HTTP Accept header enables differentiated responses
text/html             application/ld+json              application/json (fallback)
Consumer web portal   Structured DPP dataset           Generic JSON compatibility
                      (for regulators & automated systems)

Mandatory Compliance Provisions

HTTP Accept header content negotiation constitutes a binding compliance requirement. Resolver services must differentiate request types and serve corresponding payloads:

Web browser requests from end users: Return text/html formatted user interface pages
Machine-to-machine requests from regulators, recyclers and automated systems: Return application/ld+json structured documents
Interoperability fallback: Return standard application/json

ESPR compliance verification systems will actively request application/ld+json payloads. Valid structured responses must be delivered within 200 milliseconds. Redirection of JSON-LD requests to marketing landing pages will be treated as non-compliance.

2. JSON-LD: Standardised Data Payload for DPP

JSON-LD (W3C Recommendation 2020: JSON for Linked Data) has been selected by the European Commission as the primary serialisation format for DPP data exchange. In contrast to generic JSON, JSON-LD incorporates semantic context definitions, binding each data field to globally agreed terminology and enabling interoperability between heterogeneous enterprise systems.

Textile Sector DPP JSON-LD Example Payload

{
 "@context": [
 "https://schema.org",
 "https://gs1.org/voc/",
 "https://dpptex.com/contexts/dpp-textile-v1.jsonld"
 ],
 "@type": "Product",
 "@id": "https://id.brand.com/01/09506000134352/21/SERIAL-2026-K78",
 "gtin14": "09506000134352",
 "serialNumber": "SERIAL-2026-K78",
 "batchNumber": "BATCH-Q2-YARN27",
 "name": "Circular Wool Blend Overshirt",
 "description": "70% recycled wool, 30% TENCEL Lyocell",
 "manufacturer": {
 "@type": "Organization",
 "name": "Nordic Circular Textiles AB",
 "location": {
 "@type": "Place",
 "address": {
 "@type": "PostalAddress",
 "addressCountry": "SE"
 }
 }
 },
 "countryOfOrigin": {
 "@type": "Country",
 "name": "Portugal"
 },
 "material": {
 "@type": "Product",
 "materialComposition": [
 {
 "@type": "TextileMaterial",
 "name": "Recycled Wool",
 "percentageComposition": 70,
 "recycledContent": 100,
 "certification": "GRS-2025-TE-004782"
 },
 {
 "@type": "TENCEL Lyocell",
 "percentageComposition": 30,
 "certification": "Lenzing-2025-LY-1273"
 }
 ]
 },
 "sustainability": {
 "@type": "SustainabilityRating",
 "carbonFootprint": {
 "@type": "QuantitativeValue",
 "value": 8.4,
 "unitCode": "KGM",
 "unitText": "kg CO2e per kg product"
 },
 "waterFootprint": {
 "@type": "QuantitativeValue",
 "value": 2850,
 "unitCode": "LTR",
 "unitText": "litres per kg product"
 },
 "durabilityWashIndex": 78,
 "recyclabilityScore": 92
 },
 "hasGS1DigitalLink": "https://id.brand.com/01/09506000134352/21/SERIAL-2026-K78",
 "productionDate": "2026-03-15",
 "discontinuedDate": null
}

JSON-LD Core Fields – ESPR Textile Compliance Matrix

JSON-LD Field	Vocabulary Source	DPP Data Category	Mandatory under Textile ESPR
`@context`	Namespace declaration	Semantic framework foundation	Yes
`@type: Product`	Schema.org ontology	Product classification	Yes
`gtin14`	GS1 Vocabulary	Primary product identifier	Yes
`serialNumber`	Schema.org	Unit-level unique identifier	Yes
`materialComposition`	GS1 extended schema	Raw material traceability	Yes
`carbonFootprint`	Schema.org QuantitativeValue	Environmental impact metrics	Yes
`waterFootprint`	Custom extension ontology	Water consumption metrics	Mandatory audit requirement effective 2029
`durabilityWashIndex`	Custom extension ontology	Product durability indicator	Yes
`recyclabilityScore`	Custom extension ontology	Circular recovery performance	Yes
`countryOfOrigin`	Schema.org Country type	Supply chain transparency	Yes
`manufacturer`	Schema.org Organization type	DPP responsible legal entity	Yes
`certification` (per material)	Custom field	Supply chain certification traceability	Recommended
`hasGS1DigitalLink`	Proposed Schema.org extension	Self-referential Digital Link URI	Recommended
`productionDate`	Schema.org	Manufacturing timestamp	Recommended
`discontinuedDate`	Schema.org	Product lifecycle tracking	Optional

Evaluation of Data Serialisation Formats

Between 2024 and 2025, EU technical committees assessed four candidate serialisation formats for DPP deployment. The comparative assessment is summarised below:

Format	Semantic Interoperability	Native Web Resolution	Mature Tooling Ecosystem	HTML Embedding Support	Evaluation Outcome
JSON-LD	Supported (context-driven semantics)	Native URI/HTTP compatibility	Established (Schema.org, GS1 Vocabulary)	Embeddable within HTML markup	Selected official standard
Plain JSON	Absent (unregulated field semantics)	Supported	Established	Supported	Rejected – insufficient cross-system interoperability
XML (RDF/XML)	Supported (requires RDF mapping)	Supported	Established	Supported	Rejected – legacy architecture with complex parsing overhead
CSV/TSV	Absent	No native URI resolution	Limited tooling	Non-embeddable	Rejected – inadequate structured data capabilities

Key Functional Advantages of JSON-LD

A single JSON-LD document simultaneously fulfils multiple functional requirements:

Human readability for manual review via standard web browsers
Machine interpretability through standardised semantic context for automated data processing
Web-addressable ontology via globally recognised URI definitions
Native indexing capability for commercial search engine crawlers

3. CEN/CLC JTC 24: The Complete Suite of Eight DPP Standards

The European Commission mandated CEN and CENELEC Joint Technical Committee JTC 24 to develop the full portfolio of DPP technical specifications. Publication status and scope are detailed in the table below:

Standard Reference	Title	Technical Scope	Status (May 2026)	Expected Publication
prEN 18219	Unique Identifier Specifications	Cross-sector coding rules for products, batches and components	Final draft completed	Q1 2026
prEN 18220	Data Carriers and Physical-to-Digital Linkage	QR/NFC/RFID specifications, GS1 Digital Link URI syntax, resolver performance and security requirements	Final draft completed	Q1 2026
prEN 18223	Cross-Sector Interoperable Product Data	Generic data model, JSON-LD context schemas, cross-industry data dictionaries	Committee draft	Q2 2026
prEN 18216	Data Exchange Protocols and Formats	DPP system API specifications (REST, WebSocket, event-driven architectures)	Committee draft	Q2 2026
prEN 18221	Data Storage, Archiving and Long-Term Preservation	Minimum 15-year retention rules, backup protocols and business continuity requirements	Working group draft	Q3 2026
prEN 18222	Retrieval, Access and API Query Mechanisms	DPP registry search functions, access governance and API throttling frameworks	Working group draft	Q3 2026
prEN 18239	Access Rights Management and Role Hierarchies	Permission architecture for consumers, recyclers, market authorities and customs agencies	Working group draft	Q4 2026
prEN 18246	Product Data Authentication and Integrity Verification	Cryptographic integrity mechanisms, digital signature schemes and validation protocols	Committee draft	Q3 2026

Note: Final draft completion in March 2026 does not constitute a regulatory compliance deadline. Once formally published as European Standards (ENs), EU and EEA Member States are obligated to transpose these documents into national standards. Market participants are recommended to align internal systems with final draft specifications during Q2 2026. Formal compliance assessments will reference the officially released EN versions.

4. Integration of `hasGS1DigitalLink` within the Schema.org Ecosystem

GS1 and Schema.org operate a joint working group to incorporate the hasGS1DigitalLink property into the official Schema.org Product ontology. Successful adoption delivers three primary outcomes:

Automated DPP discovery by search engine crawlers via recognised structured markup
Native support for automated data retrieval by artificial intelligence platforms for sustainable product benchmarking
Low-effort upgrade pathway for operators already implementing Schema.org product metadata, avoiding full system redesign

5. Industry Misconceptions Regarding DPP Implementation

Misconception: DPP can be delivered as PDF documents ESPR technical annexes mandate machine-readable structured data. Static PDF files support only manual human review and cannot be processed automatically by compliance verification systems, sorting infrastructure or digital analytics platforms. Regulatory guidance confirms PDF-only deployments constitute non-compliance.
Misconception: DPP datasets are centrally hosted on government servers EU central registries store only identifiers, linkage metadata and public verification keys. Full product datasets remain under the custody of brand owners or authorised third-party DPP service providers.
Misconception: DPP records are static and immutable DPP datasets support continuous updates across the full product lifecycle, accommodating batch revisions, safety recalls, recalculated environmental metrics and other lifecycle events.
Misconception: DPP obligations apply exclusively to newly manufactured goods Proposed revisions to the Waste Framework Directive introduce requirements for retrospective DPP records applicable to second-hand and vintage goods traded within the EU, effective 2029.

6. Enterprise Implementation Roadmap

Secure dedicated resolver domain (Q2 2026) GS1 Digital Link deployments require an SSL-enabled, enterprise-controlled DNS domain (e.g. id.brand.com). Finalise domain ownership prior to resolver service rollout in Q3.
Allocate GTINs for all SKUs; complete unit-level serialisation (Q4 2026) Organisations not yet participating in the GS1 system shall engage national GS1 authorities to assign 14-digit GTINs. Establish serial number generation workflows for individual unit identification.
Develop JSON-LD DPP templates proactively Core mandatory fields including GTIN, serial number, material composition, environmental metrics, manufacturer information and origin data are stable. Organisations may deploy base templates and incrementally extend schemas following formal standard publication.
Implement HTTP content negotiation within resolver infrastructure Build differentiated response logic triggered by the HTTP Accept header. Validate functionality via test requests: curl -H "Accept: application/ld+json". Redirection of structured data requests to marketing pages is prohibited.
Deploy global CDN infrastructure to optimise latency Compliance audits require resolver response times within 200 milliseconds. Enterprise-grade global CDN services are recommended to meet latency requirements.
Decommission PDF-only information architectures QR codes delivering only PDF downloads represent legacy non-compliant solutions. Operators must transition fully to JSON-LD structured data architectures ahead of formal enforcement timelines.

7. Technical & Regulatory References

GS1 General Specifications Version 23 (2024); GS1 Digital Link Standard v1.4
ISO/IEC 18975:2024
W3C JSON-LD 1.1 Recommendation (2020)
Schema.org Official Product Type Documentation
CEN/CLC JTC 24 Work Programme 2025–2026
Regulation (EU) 2024/1781 (ESPR), Article 31 and Annex III
GS1–Schema.org Joint Working Group: hasGS1DigitalLink Property Specification (2025–2026)
European Commission Joint Research Centre (JRC), DPP Data Architecture Technical Report, February 2026

Supplementary Industry Perspectives

Cross-domain interoperability: Data space alignment for Catena‑X, Gaia‑X and SEMI. API gateway architecture options to enable secure data exchange amid globalised, fragmented supply chain ecosystems.
Global electronics standardisation: Approaches to align digital traceability requirements across East Asian manufacturing regions, Japan, Taiwan and the EU.
Standardised DPP deployment based on GS1 Digital Link syntax: Engineering framework for consistent physical data carrier addressing under ESPR regulation.

Extended Reference Materials

European Commission ESPR Guidance Documents (EUR-Lex Circular Economy Directives and Mandates)
GS1 Global Standards Library (GTIN‑14, resolver service architecture specifications)
W3C Verifiable Credentials VC 2.0 (cryptographic validation protocols, JSON-LD syntax)
ISO management system portfolio (ISO 17025 laboratory testing competence standard)