Regulation & Policy
Very Large Online Search Engine
Also known as: VLOSE, VLOSE designation
A Very Large Online Search Engine, or VLOSE, is a designation under the European Union's Digital Services Act for search engines that reach more than 45 million average monthly active users in the EU. Designated services face extra duties on risk assessment, transparency, auditing and researcher data access, and are supervised directly by the European Commission. Google Search and Microsoft Bing were among the first services designated.
What it is
VLOSE is a legal category created by the Digital Services Act, sitting alongside the Very Large Online Platform, or VLOP, category. Designation is based on user reach in the EU rather than on revenue or market share. Once designated, a search engine takes on the most demanding tier of obligations in the regulation.
Why it matters
The designation shapes how the largest search engines document ranking systems, handle illegal and harmful content, and explain advertising and recommender behaviour in Europe. For marketers, it means more published information about how results and ads are selected, plus formal complaint and appeal routes when content is demoted or removed. It also helps explain why some features and disclosures appear in the EU before, or differently from, other regions.
How it works
Designated services must run periodic systemic risk assessments, put mitigation measures in place, commission independent audits, publish transparency reports, and give vetted researchers access to data. They also have to describe the main parameters of their recommender and ranking systems in terms users can understand, and offer a way to report illegal content. The European Commission acts as the supervisor and can open proceedings where it believes obligations are not met.
When it applies
The concept applies when you are assessing regulatory risk, reading search engine transparency documentation, or planning content and advertising that reaches EU audiences. It is also relevant background when explaining to stakeholders why search disclosures and appeal mechanisms differ inside the EU.
Examples
- A compliance team cites VLOSE transparency reports when reviewing how a search engine handles removal requests in the EU.
- An SEO lead uses a designated engine's published description of ranking parameters to brief the leadership team on how results are selected.
- A publisher appeals a content demotion using the complaint route a designated search engine is required to provide for EU users.
How it is measured
- EU visibility and click share on designated search engines, tracked separately from other markets
- Volume and outcome of content or listing complaints and appeals submitted in the EU
- Frequency of transparency report and audit publications reviewed for changes affecting your sector
- Regulatory watch log of Commission proceedings or guidance that could change ranking or ad disclosure
Insights on Very Large Online Search Engine
Related terms in Regulation & Policy
- AI complianceAI compliance is the work of making sure AI systems meet the laws, regulations, standards and internal policies that apply to them. It spans data protection, transparency, risk classification, documentation, human oversight and record keeping across the life of a system. In practice it combines legal interpretation, engineering controls and ongoing evidence gathering.
- AI governanceAI governance is the set of policies, roles, controls and review processes an organisation uses to manage how AI systems are built, bought and used. It covers risk assessment, documentation, human oversight, data handling and accountability. It applies both to AI a company develops and to third-party AI tools used by staff.
- AI privacyAI privacy is the set of practices, rights and obligations that govern how personal data is collected, used, stored and exposed when building or using AI systems. It covers training data, prompts and outputs, retention by AI vendors, and the transparency and control offered to the people whose data is involved. For marketing teams it shapes what customer data can safely be put into AI tools and what must be disclosed.
- AI safetyAI safety is the practice of designing, testing and operating AI systems so they cause less harm, behave predictably and resist misuse. It covers alignment with intended behaviour, evaluation and red teaming, content guardrails, and monitoring once a system is live. For marketers it shapes what models will say, how assistants handle brands, and what compliance teams expect before AI tools go into production.
- AI transparencyAI transparency is the practice of making clear how an AI system works, what sits behind it, and when content or an interaction involves AI. It covers regulatory disclosure duties as well as voluntary explanations such as model cards, labels on synthetic media and citations in AI generated answers. For publishers and marketers it sets expectations about when AI involvement should be declared and how clearly.
- Competition and Markets AuthorityThe Competition and Markets Authority (CMA) is the United Kingdom's competition and consumer protection regulator. It investigates mergers, anti-competitive conduct and market practices, and it holds specific powers over large digital firms under the Digital Markets, Competition and Consumers Act 2024. Its decisions shape how search engines, app stores and AI assistants operate in the UK market.
Primary research · August 2026
How ChatGPT Shortlists Software Brands
An audit across 10 categories and 60 buying questions. I recorded what ChatGPT reads, throws away and links to when a buyer asks it which software to buy, and what that decides.
- 60
- Questions asked
- 10
- Software markets
- 2,680
- Results read
- 367
- Links shown
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