HTML4EU – Towards smarter, more accessible legal publications

The Publications Office (OP) has launched an exciting project called HTML4EU, marking another step forward in modernising the way legal documents are published and shared. The HTML4EU initiative aims to establish a single, standard HTML format for all legal publications on EUR-Lex.

This initiative will be introduced in the context of AKN4EU, the new interinstitutional exchange format for legal documents. To make the most of this standard, OP is setting up a process to represent AKN4EU source files in RDFa-augmented HTML – the web’s standard language enriched with linked data semantics – ensuring that online EU legal content is more accessible, reusable, interoperable, and consistent.

Fitting the pieces together - How the EUR-Lex HTML format relates to the other main specifications or needs

The goal is not only to modernise how legal information is displayed, but also to make it easier to maintain, share, and improve over time, ensuring consistency with key references like the Interinstitutional Style Guide (ISG), web content accessibility guidelines (WCAG), and the pillars of the European Legislation Identifier (ELI).

A key element of this project is the adoption of a comprehensive validation chain that combines SHACL shape validation for RDF data with HTML linting tools. In simple terms, this means that instead of relying only a rigid set of syntax rules, OP teams can combine them with flexible, business-defined checks and behaviours. This approach ensures high standards of structural and stylistic quality, accessibility, and consistency, while fitting seamlessly into the automated workflows and continuous validation objectives of the Publications Office.

As a result, HTML4EU will make legal content easier to read, navigate, and reuse – both for citizens and developers.
By combining modern technology with strong foundations such as AKN4EU, RDFa, and the HTML standard, the Publications Office is building a more open, interoperable, and future-proof way to publish EU law on the web.