In short. DSA Article 27 requires covered online platforms to explain their main recommender parameters and available controls, while Article 38 adds an option without profiling for designated very large services.
Definition: Under Article 27 of the Digital Services Act (DSA), covered online platforms must explain the main parameters of systems that automatically suggest or prioritise information, called recommender systems. They must describe any options for users to modify or influence those parameters.
Key facts
- DSA Article 27 requires the explanation in the platform's terms and conditions, in plain and intelligible language.
- The European Commission's DSA questions and answers explains that very large platforms and search engines have additional obligations and identifies a threshold of at least 45 million users.
- General Data Protection Regulation (GDPR) Article 4(4) defines profiling as automated processing of personal data to evaluate personal aspects, including analysing or predicting interests or behaviour.
Which services fall within the rules?
The DSA's scope and definitions cover intermediary services offered to recipients established or located in the EU, wherever the provider is established. Article 3(i) defines an online platform as a hosting service that stores and publicly disseminates information at a recipient's request, subject to an exception for minor ancillary features. Article 27 addresses providers of these platforms when they use recommender systems.
Article 3(s) includes systems that determine information's relative order or prominence, including following a user's search. The definition therefore covers more than personalised feeds.
Article 19 generally exempts micro and small platform providers, as defined in Recommendation 2003/361/EC, from the section containing Article 27. It also provides a transitional exemption for 12 months after loss of that status, except for very large online platforms. Designation as a very large online platform overrides the size exemption. Article 93 sets the DSA's general application date at 17 February 2024.
What must the parameter explanation contain?
Article 27(2) requires an explanation of why particular information is suggested. It identifies the following minimum elements:
the criteria which are most significant in determining the information suggested to the recipient of the service;
the reasons for the relative importance of those parameters.
The provision concerns both the selection criteria and why those criteria have their relative importance. Recital 70 also identifies prioritisation based on profiling and online behaviour as relevant to the explanation.
Article 27(3) adds an interface requirement where several recommender options are available for ordering information. Users must be able to select and change their preferred option at any time. The control must be directly and easily accessible from the part of the interface where information is prioritised. A review therefore examines both the written explanation and the location of the control.
What changes for very large services?
Article 38 requires providers of designated very large online platforms and very large online search engines using recommender systems to offer at least one option for each system without profiling. It expressly adds this duty to Article 27's requirements.
Article 33 combines an audience threshold of at least 45 million average monthly active recipients in the EU with a Commission designation decision. The additional section's obligations apply four months after notification of designation. For AI search, this makes service classification and designation the starting points for assessing these duties.
Related terms
FAQ
Does my business website need a recommender explanation?
Article 27 addresses providers of covered online platforms using recommender systems. Assess your service against Article 3(i)'s hosting and public-dissemination definition and Article 19's exemption.
Where should I find the explanation and controls?
Under Article 27, the explanation belongs in the terms and conditions. Where several ordering options are available, the selector must be directly and easily accessible where the platform prioritises information.
Must every covered platform offer an option without profiling?
Article 38 assigns that additional duty to designated very large online platforms and search engines using recommender systems. Article 27 requires disclosure of any parameter controls and a selector where several ordering options are available.
Sources
- European Parliament and Council, "Regulation (EU) 2022/2065 (Digital Services Act)", 27 October 2022
- European Commission, "Digital Services Act: Questions and Answers", 19 December 2025
- European Parliament and Council, "Regulation (EU) 2016/679 (General Data Protection Regulation)", 4 May 2016
Check how a page reads to answer engines. Open the GEO score analyzer