Updated
Updated What changed on
Fact-checked Only the fan-out sub-query count, the Google guide's title, Google's wording on which surfaces may use fan-out, the Ahrefs ChatGPT fan-out figure and the Ahrefs citation study comparison were re-checked against the 14 October 2026 source checks. Nothing else on the page was re-checked.
- Removed the claim that fan-out produces 5 to 7 sub-queries. Google does not publish how many sub-queries it runs.
- Corrected the name of Google's guide: it is Optimizing your website for generative AI features on Google Search (May 2026, updated July 2026), not an "AI Optimisation Guide".
- Corrected which Google surfaces use fan-out: Google says AI Overviews and AI Mode may both use it, and it does not say AI Overviews uses a lighter version.
- Relabelled the example sub-query list as illustrative, since Google does not publish the sub-queries it runs.
- Added an Ahrefs sample of ChatGPT responses from August and September 2026 (published October 2026): ChatGPT searched the web in only 14.4% of responses, and ran about 1.6 fan-out queries on average when it did.
- Removed the line calling the Ahrefs March 2026 study proof that cited pages are drifting away from ranked pages. Ahrefs changed how it counts citations between its 2025 and 2026 studies, so the two years are not like for like.
What is query fan-out, and how do you win it?
The 30-second answer
Query fan-out is when an AI search engine takes one user prompt and decomposes it into several related sub-queries, runs each separately, then synthesises the answers. Google says AI Overviews and AI Mode may both use query fan-out, and it does not publish how many sub-queries they run. Its May 2026 guide, Optimizing your website for generative AI features on Google Search, names query fan-out as one of the mechanics. The implication for content: pages that bundle the parent topic plus related sub-questions on the same URL get cited multiple times across the synthesis. Pages that target only the headline query compete in one round and lose to bundled pages competing in four.
What fan-out does to the citation set
of URLs cited in Google AI Overviews appeared in the first 10 results blocks for that query. Ahrefs counts blocks, not organic results, so this is not the same as ranking in the top 10.
How it was measured: 863,000 keyword SERPs and 4 million AI Overview URLs. Ahrefs measures the top 10 as blocks, counting ads, featured snippets and video packs as separate blocks.
of AI Overview citations that do not rank in the top 100 are YouTube URLs.
How it was measured: Same 863,000 SERP dataset. YouTube accounts for 5.6% of all AI Overview URLs cited across the dataset.
How fan-out actually works
User types: "best AI search rank trackers for UK B2B in 2026". Google AI Mode internally decomposes that into something like:
Illustrative sub-queries (Google does not publish the ones it runs):
- What are AI search rank trackers
- Best AI search rank trackers 2026
- Pricing of AI search rank trackers
- AI search rank trackers for B2B
- UK-based AI search rank tracker options
- Comparison of Profound vs AIClicks vs Otterly
- What changed in AI rank tracking in 2026
Each sub-query hits the retrieval system independently. Different pages get retrieved for each. The engine then composes one answer by stitching extracts from the winning pages per sub-query.
What this means for your pages
A listicle that ranks for "best AI search rank trackers UK 2026" only competes in one of those seven example sub-queries. The other six go to pages that happen to answer them - pricing pages, comparison pages, what-is pages, vertical-specific pages. The bundled page beats the focused page on total citation share.
Primary sources on fan-out: Google's official AI search guidance (May 2025) names the technique, Ahrefs' Jan 2026 AI Mode analysis measures sub-query depth, Google's own AI Mode launch post describes the multi-step reasoning, and Moz's AI Mode content strategy guide covers the content-shape implications.
If you are applying this to Google specifically, the practical page is the Google AI Mode optimisation guide. That is where fan-out matters most because one prompt can become several retrieval rounds.
The pattern that wins fan-out
Cover the parent query plus the predictable sub-questions on the same URL. For a listicle:
- Pricing snapshot per tool - one row, vendor + plan + monthly price in your currency.
- "Best for [use case]" mini-note per tool - 1-2 sentences.
- Head-to-head row in a comparison table - tables get extracted as structured facts.
- "What changed in 2026" per tool - addresses the recency sub-query.
- One paragraph on category vocabulary - addresses the "what are X" sub-query.
For non-listicle pages
Same principle, different shape. A service page should cover: what the service is (definitional sub-query), what it costs (pricing), what alternatives exist (comparison), what changed recently (recency), who it suits (audience). Five sub-queries answered on one URL.
What does NOT help fan-out
- Making a single page longer in word count without expanding topic coverage.
- Cross-linking to separate pages for the sub-topics. Fan-out rewards the page that bundles, not the network of separately ranked pages.
- Keyword stuffing the sub-queries into prose. Each sub-question needs its own answer block to be extracted.
The four types of fan-out queries
Not every fan-out sub-query looks the same. Ahrefs' March 2026 analysis grouped them into four working categories worth knowing because each one suggests a different content shape to bundle on your page:
- Reformulation queries. The same intent, restated in a different vocabulary. For "best AI search rank trackers UK 2026" the engine also runs "top GEO citation tracking tools" and "AI visibility platforms for UK marketers". Win these by using synonyms and category-vocabulary in your H2s, not just the head keyword.
- Expansion queries. The original intent plus an attribute the user did not type. "Best running watch" expands to "best running watch with GPS", "best running watch under £200", "best running watch for marathon training". Win these with attribute-by-attribute sections (pricing tier, use case, persona).
- Sub-topic queries. Related but distinct intents that complete the user's mental model. For "what is GEO" the engine fans out to "how does GEO differ from SEO", "GEO ROI", "GEO tools". Win these with sibling H2s that answer each one explicitly.
- Comparison queries. "X vs Y" patterns the engine generates even when the user did not. For "best UK CRM" the engine runs "HubSpot vs Pipedrive", "Salesforce vs Zoho", etc. Win these with a comparison table on the listicle plus dedicated vs/compare pages linked from it.
The single-page test: ask yourself which of the four types your page currently answers. Most pages cover the head plus one type (usually expansion). Pages that cover all four win disproportionately because they get retrieved in three to four times more fan-out rounds.
More on fan-out.
What is query fan-out?
Query fan-out is the technique where an AI search engine takes a single user prompt and decomposes it into several related sub-queries, runs each one, then synthesises the answers. Google says AI Overviews and AI Mode may both use query fan-out, and it does not publish how many sub-queries they run. Its guide, Optimizing your website for generative AI features on Google Search (May 2026, updated July 2026), names query fan-out as one of the mechanics.
How does query fan-out change SEO?
Pages that bundle pricing, use-case, comparison and feature passages win citation across multiple sub-queries from one user prompt. A page optimised purely for the headline competes in only one fan-out round. A page covering related sub-questions on the same URL can be cited multiple times across the synthesised answer.
Which engines use query fan-out?
Google says AI Overviews and AI Mode may both use query fan-out. In an Ahrefs sample of free, logged-out ChatGPT responses from August and September 2026 (published October 2026), ChatGPT searched the web in only 14.4% of responses, and ran about 1.6 fan-out queries on average when it did. Perplexity uses related decomposition patterns under different names. The principle is the same across modern AI search: one prompt becomes multiple retrievals.
Should I make my pages longer to win query fan-out?
Not longer for the sake of it. Wider in topic coverage. A 1,500-word page that covers the parent topic plus three related sub-questions earns more fan-out citations than a 4,000-word deep dive on the parent only.
How does query fan-out affect listicles?
A best-of-X listicle that only ranks the tools competes in one fan-out round. Add pricing tables, "best for [use case]" notes per tool, comparison rows, and a "what changed in [year]" line and the same listicle competes in four to six rounds.
Jason Burns
Independent UK SEO, GEO and AI consultant. In search since 2007. Portfolio includes 3M, BlackRock, Unilever and E.ON. Owner of SEO Moves Ltd since 2014.
More about Jason →Want me to audit one page for fan-out coverage?
Send one priority page. I write up the five sub-queries the engine will probably decompose into, then mark which ones the page already answers and which gaps to close. Short, written.
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