AI Mode is Google's AI search experience, launched in Labs in March 2025 and rolled out in the US in May 2025. Google confirms it uses a query fan-out technique: it breaks a question into subtopics and issues many related searches at once, then combines the results into one response with links. Google says there are no extra technical requirements beyond being indexed and eligible for a snippet. For sites, fan-out means visibility depends on answering the subquestions behind a topic, not only the head query.
What is AI Mode and query fan-out?
AI Mode is a Google Search mode that answers with an AI generated response and links to the web, built on a custom version of Google's Gemini models. Query fan-out is the technique Google says it uses underneath: the question is broken into subtopics, many related searches are run at once, and the results are combined.
Google introduced AI Mode as a Labs experiment in March 2025 and rolled it out in the US in May 2025.
It uses a "query fan-out" technique, issuing multiple related searches concurrently across subtopics and multiple data sources and then brings those results together to provide an easy-to-understand response.
Robby Stein, Google, Expanding AI Overviews and introducing AI Mode, Google Blog
How does query fan-out work?
Google's descriptions are consistent across posts. The model plans the searches, runs them in parallel across the web index and other sources, and synthesises one answer. The March 2025 post names the Knowledge Graph and shopping data among those sources.
Google has described larger versions of the same method. Deep Search, announced in May 2025, uses fan-out to issue hundreds of searches for a research report. A March 2026 Google explainer describes AI Mode running several visual searches at once for objects in a single image.
Google's AI features documentation says both AI Overviews and AI Mode may use fan-out, and that they may use different models and techniques, so the links each shows will differ.
Under the hood, AI Mode uses our query fan-out technique, breaking down your question into subtopics and issuing a multitude of queries simultaneously on your behalf.
Elizabeth Reid, Google, AI in Search: Going beyond information to intelligence, Google Blog
What evidence is there that Google uses query fan-out?
The evidence label is Confirmed. Google names the technique in its AI Mode launch post, its May 2025 update and its Search Central AI features guide.
What Google has not published is how many subqueries a typical AI Mode answer uses, how subtopics are chosen, or how cited pages are selected from the combined results. Any specific number of fan-out queries quoted by third parties is their measurement or estimate, not Google's figure.
AI Mode is rooted in our core quality and ranking systems
Robby Stein, Google, Expanding AI Overviews and introducing AI Mode, Google Blog
How does a page become eligible to appear in AI Mode?
Google's rules are short. A page must be indexed and eligible to show in Search with a snippet. There is no special markup, file or schema. That makes snippet controls the main technical lever: a page with nosnippet or max-snippet set to 0 cannot be a supporting link.
To be eligible to be shown as a supporting link in AI Overviews or AI Mode, a page must be indexed and eligible to be shown in Google Search with a snippet, fulfilling the Search technical requirements.
What should sites do about query fan-out?
Because fan-out runs many related searches for one question, a site competes on the subquestions around a topic, not only the head query. The testable step is a coverage map: list the subtopics a question naturally breaks into and check whether the site has a page or a clearly headed section for each.
This is a hypothesis about citation, not a Google guarantee. Google has not said coverage of subtopics increases citation. Measure it by tracking which of your pages appear as AI Mode links before and after filling gaps, and treat results on a handful of queries as anecdote.
- Confirmed by Google: fan-out exists, pages need to be indexed and snippet eligible, and no special markup or files are needed.
- Not confirmed: that more subtopic coverage raises citation rates, or any published count of fan-out queries.
Which Laurelin audit checks test for AI Mode and query fan-out?
The eligibility checks test Google's documented requirements. The coverage check is a proxy; fan-out subqueries are not shown to site owners.
Fan-out subtopics of a core question have no matching page or section: the new check for this page.
Meta robots nosnippet kills AI feature eligibility: Google requires snippet eligibility.
Max-snippet 0 directive: the same requirement, set another way.
Data-nosnippet wrapping primary content: hides the content fan-out would draw on.
Passages not self-contained: a section answering one subquestion should stand on its own.
AI-only machine readable mirror files: Google says no new AI files are needed to appear.
What are the key dates for query fan-out?
Frequently asked questions about query fan-out
What is query fan-out?
It is the technique Google says AI Mode uses: breaking a question into subtopics, running many related searches at once, and combining the results into one response with links.
Do I need special markup or an AI text file to appear in AI Mode?
No. Google says a page only needs to be indexed and eligible to show with a snippet, and that no new machine readable files or special schema are needed.
How many searches does query fan-out run?
Google has not published a typical number. It has said Deep Search can issue hundreds of searches, which is a separate, larger use of the same technique.