VLOSE stands for Very Large Online Search Engine, the Digital Services Act's designation for a search engine with more than 45 million average monthly EU users. Designation triggers systemic-risk assessments, independent audits, researcher data access, and, for ad-serving platforms, a public ad repository under Article 39.
VLOSE is one of two size-based designations under the Digital Services Act, alongside VLOP (Very Large Online Platform). Both trigger the DSA's heaviest compliance tier, but VLOSE applies specifically to search engines, judged against a threshold of more than 45 million average monthly users in the EU.
The European Commission designated ChatGPT a VLOSE on August 31, 2026, the first AI chatbot to receive the label, based on roughly 159.1 million average monthly EU users. Designated platforms get four months to comply, which for ChatGPT lands the deadline in January 2027.
VLOSE status is what turns a platform's reach into a legal obligation. Crossing the threshold switches on systemic-risk assessments, independent audits, researcher data access and, for ad-serving platforms, a public ad repository under Article 39, automatically.
For competitive researchers, a platform crossing the VLOSE threshold is the clearest signal that its ad data is headed toward a public repository, on the DSA's compliance timeline rather than the platform's own.
