What does DSA Article 27 require for recommender system transparency?
Article 27 applies to providers of online platforms that use recommender systems. The DSA defines a as a fully or partly automated system that suggests information, prioritises it, or determines the relative order or prominence of information in the platform interface.
The platform must set out, in its terms and conditions and in plain, intelligible language, the main parameters used by the and any options recipients have to modify or influence those parameters. Article 19 can exclude qualifying micro and small online-platform providers from Article 27, subject to the post-loss transition and the rule that designated VLOPs remain covered.
- Identify every recommender surface: feed, search results, marketplace ordering, content suggestions, ranking modules, or other interface areas that suggest or prioritise information.
- Describe the most significant criteria used to determine what information is suggested to a user.
- Explain why those parameters have their relative importance; do not replace this with an unexplained formula, model name, or generic personalization statement.
- List the user options that can modify or influence the main parameters, or state clearly when no such option is offered for that recommender surface.
Does the EU Digital Services Act require platforms to publish the full recommender algorithm?
No. Article 27 is framed around plain-language disclosure of the main parameters and user options, not publication of source code, model weights, or a technical formula. The explanation should let a recipient understand why certain information is suggested and which criteria matter most.
Article 3 defines recommender systems, and Article 27 requires plain-language disclosure of main parameters and user options in terms and conditions.