What is Query fan-out?
Nati Elimelech·Updated 24.07.2026 Query fan-out is the process where an AI engine breaks one prompt into dozens of sub-queries, runs them in parallel, and assembles the results into a single answer.
When you ask ChatGPT or Gemini a question, they almost never run one search. Behind the scenes the prompt breaks into dozens of small queries: different phrasings of the intent, follow-up questions, targeted site: searches, and checks on specific entities. Each query returns sources, and the engine assembles them into the answer the user sees.
A prompt like “what car suits young drivers” can fan out into queries about safety, running costs, insurance for new drivers and specific models. Whoever shows up in the sub-query results is in the raw material of the answer.
How it relates to SEO and GEO
Sub-queries are the keyword research of the AI era: they reveal what the engine actually searches when someone asks about your field, which entities it checks, and which sources it builds answers from. Tracking the fan-out gives you a target list to cover, straight from the system. The full breakdown is in the query fan-out article.