
AI systems such as ChatGPT, Gemini and Perplexity don’t always answer a prompt by running a single search. Instead, they often expand the original question into multiple related searches to research the topic before generating a response.
During this process, the model may explore different aspects of the query, retrieving information from a range of sources. These additional searches are known as ‘query fan-outs’.
Understanding how query fan-outs work is becoming increasingly important for generative engine optimisation (GEO), because they reveal how AI systems actually research and create answers.
They influence:
As a specialist GEO agency, we analyse this behaviour through controlled experiments to understand how AI models retrieve information, expand prompts and determine which sources to cite.
Let’s break down what query fan-outs are, how they work, and how AI models expand queries when researching a topic.
A query fan-out describes how an AI model expands a single user prompt into multiple related questions or searches when researching a topic.
Rather than relying on one query, the model generates several additional searches that explore different aspects of the topic. These searches allow the system to find relevant information across websites before producing an answer.
The results are then combined to generate a single AI response.
In simple terms, the process looks like this:
One prompt → Multiple related searches → One AI-generated answer
This is the process AI systems use to research a topic before producing a response.
Query fan-outs influence which sources AI systems discover when researching a topic.
When an AI model expands a prompt into multiple related searches, each query can retrieve different sources and perspectives. The model then combines these results to produce its final answer.
This means visibility in AI-generated responses is not determined by ranking for a single keyword. Content can be discovered through many related searches during the model’s research process.
For brands and publishers, this changes how content appears in AI systems. Pages that cover a topic in depth and answer several related questions are more likely to be retrieved across these fan-out searches, strengthening topical authority.
By analysing query fan-outs, you can see how AI systems actually research a topic.
Each fan-out query can retrieve different sources and perspectives, revealing how the model builds its understanding of a topic. Mapping these prompts reveals how the model researches a topic and which sources it retrieves.
This analysis can reveal:
Which sources are consistently retrieved
Which topics models explore around a query
Where competitors appear across these searches
Where your content is missing entirely
These insights help explain why some brands appear regularly in AI-generated answers while others remain invisible.
To understand query fan-outs, it helps to think about how an AI system researches a question.
For example, a user might ask: "What are the best family holidays?"
From here, the model will expand the prompt into several related queries, such as:
Best destinations for family holidays
Family holiday resorts with kids clubs
Cheapest family holidays in Europe
Best family beach holidays
Family holidays with waterparks
Each of these searches explores a different aspect of the topic and helps the model find relevant information before generating its final answer.
Large language models (LLMs) aim to answer a user’s question as accurately and completely as possible.
To do this, they expand the original prompt into several related questions that help them build a fuller understanding of the topic at hand. These additional searches help the model gather information from different sources before generating its response.
Query fan-outs help AI models:
Understand the intent behind a question
Find information from multiple sources
Check facts across different websites
Build more comprehensive answers
This is why a single AI response often includes information pulled from many different pages.
When a prompt is submitted to an AI tool, like ChatGPT or Gemini, the model often performs a short research step before generating its answer. During this stage, the model runs several related searches and combines the information it finds into a single response.
This process typically involves three stages:
The system first determines what the user is actually looking for.
For example, a prompt like "best family holidays" may imply:
The model then generates multiple related searches that explore the topic more comprehensively.
These queries often include:
Information is retrieved for each expanded query and combined to produce a single response. This is why AI answers often draw on information from several different pages.
When analysing how AI systems expand prompts, fan-outs tend to fall into several common patterns. While the exact structure varies between models, most fan-outs include combinations of the following six query types.
These categories help explain how AI systems explore a topic during the research process.
Definition queries help the system understand the topic itself and establish the core concepts behind a prompt.
Examples:
Comparison queries evaluate different options or approaches in order to generate recommendations.
Examples:
Feature queries explore specific attributes that users may care about when making a decision.
Examples:
Informational queries expand the research around planning, logistics, and travel advice.
Examples:
Transactional queries relate to booking intent and commercial options.
Examples:
Validation queries help models cross-check information across multiple websites before generating its answer.
Examples:
Let’s look at the prompt "best family holidays".
A simplified fan-out might look like this:
|
Original prompt |
Expanded queries |
|---|---|
|
best family holidays |
best family holiday destinations |
|
family resorts with kids clubs |
|
|
cheap family holidays in Europe |
|
|
family holidays with waterparks |
|
|
best time to travel with kids |
Each query explores a different aspect of the topic, helping the model gather the information needed to produce the final answer.
Understanding how query fan-outs work is useful, but analysing them provides much deeper insight into how AI systems research a topic.
A simple process can help you map fan-outs for any search query.
For example, mapping the fan-outs for a query like "best family holidays in Europe" often reveals dozens of related prompts, each retrieving different sources and perspectives.
Want to analyse fan-outs for your own industry? Download our query fan-out analysis worksheet.
Query fan-outs directly influence which sources appear in AI-generated answers.
When an AI model expands a prompt into multiple related queries, each search retrieves information from different pages. These results are then combined to produce the final response.
Pages that answer several of those related queries are more likely to appear in the model’s research process.
For example, a page covering family holiday destinations, resorts with kids' clubs, and the best time to travel with children may surface in response to several fan-out queries. This increases the likelihood that the page will be retrieved and cited by AI systems.
This is one reason why topical depth and structured content are becoming increasingly important for both SEO and GEO.
Rather than targeting a single keyword, strong pages answer multiple related questions and cover a topic in depth. This makes them more useful for both traditional search engines and AI systems in researching a topic.
These insights often inform broader strategies such as AiPR™ campaigns, which focus on earning authoritative mentions in sources AI systems trust.
Query fan-outs behave very similarly to long-tail keyword research (and targeting ‘low-hanging fruit’), but operate around conversational prompts rather than traditional keywords.
AI models explore networks of related queries when researching a topic. This means search strategies should focus on topic coverage rather than isolated keywords.
Strong pages often cover:
The main query
Related questions
Comparisons
Supporting information
This is one reason why data-led assets often perform well across both search engines and AI systems. Their depth, originality and topical relevance make them useful across multiple fan-out queries.
Authority signals also influence which sources AI systems retrieve. Editorial coverage and high-quality links earned through Digital PR help strengthen the credibility of pages AI models cite.
Query fan-outs are a core concept within generative engine optimisation (GEO).
When we run a GEO audit, we analyse how AI systems expand prompts into related queries and which websites appear across those searches.
This helps us understand:
For example, analysing travel prompts such as "family holidays" often reveals fan-out queries related to destination comparisons, resort features and travel planning advice.
If a brand only targets the main keyword, it may miss visibility across this wider set of related searches.
Understanding these fan-outs helps brands improve their visibility across multiple AI research paths rather than relying on a single query.
Our GEO audits analyse prompt fan-outs, citation patterns and brand visibility across major AI platforms to identify where your brand appears in AI answers, and where opportunities exist.
Query fan-outs are a core part of how AI systems research information.
Understanding them helps explain:
This means the focus is moving away from targeting keywords to covering topics in depth. The more related questions your content answers, the more opportunities AI systems have to discover, retrieve and cite your pages.
This is how brands 'win' visibility across both traditional search and AI search.
Query fan-outs are the additional searches an AI model generates when researching a topic. Rather than relying on a single query, the system expands the original prompt into several related searches to gather information before producing an answer.
AI models use query fan-outs to better understand the intent behind a question. By exploring several related searches, they can gather information from different sources and produce more complete answers.
Query fan-outs influence which pages AI systems retrieve when researching a topic. Content that answers several related queries is more likely to be discovered and cited in AI-generated responses.
Marketers can analyse fan-outs to see how AI systems explore a topic. This helps identify content gaps, improve topic coverage and increase the chances of being cited in AI answers.