XML vs JSON-LD: Data Formats for Product Passports

Two Approaches to Structured Data

XML (eXtensible Markup Language) and JSON-LD (JavaScript Object Notation for Linked Data) are both capable of representing the structured product data required for Digital Product Passports. However, they differ significantly in complexity, web compatibility, and adoption trends.

Understanding these differences helps organisations choose the right format for their DPP implementation and data exchange needs.

XML: The Established Standard

XML has been the dominant format for enterprise data exchange for decades. It offers strong schema validation through XSD, mature tooling, and widespread enterprise system support.

However, XML has notable drawbacks for DPP use cases:

• Verbose syntax with significant overhead from opening and closing tags
• Complex schema definitions that require specialised expertise
• Limited native support in modern web browsers and JavaScript frameworks
• No built-in mechanism for semantic linking between datasets

JSON-LD: The Web-Native Choice

JSON-LD has emerged as the preferred format for DPP data exchange. It offers a compact, readable syntax and is natively supported by web technologies. Its linked data capabilities enable semantic interoperability, machines can understand the meaning of data, not just its structure.

Key advantages for DPP implementation include:

• Compact syntax: typically 30-50% smaller than equivalent XML
• Web-native: works with standard HTTP and REST APIs
• Semantic context: @context maps properties to standard vocabularies
• Search engine compatible: understood by Google and other search engines
• Simpler tooling: any JSON library can process JSON-LD

Choosing the Right Format

For new DPP implementations, JSON-LD is the recommended choice. It aligns with the web-first approach of the ESPR, supports semantic interoperability, and offers simpler implementation. XML may still be relevant for integration with legacy enterprise systems.

MyProductPassport uses JSON-LD as its primary data format, with content negotiation supporting multiple output formats to meet diverse stakeholder needs.