What is query fan-out in AI search?

Published 3 min read

Our numbers: OpenAI model (gpt-5.6-luna) via Codex CLI with web search, not the ChatGPT app. 01-02.11.2026, 13 software questions, 115 runs.

Query fan-out is how AI search turns one question into many smaller searches. Here is how it works, with Google's own words and an example.

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What does query fan-out mean?

Query fan-out means an AI search tool splits one question into several smaller searches. It runs them, reads the results, and writes one answer from what it found. Google says AI Mode and AI Overviews may use it. So a page can be found for a sub-question the buyer never typed.

How does Google describe query fan-out?

Google uses the term itself. It says AI Mode splits your question into subtopics and searches for many at once.

  • Google Search blog, May 2025

    "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."

  • Google Search Central

    Both AI Overviews and AI Mode may use it. Google says this lets it show a wider set of links.

What does fan-out look like for one question?

Below is an illustration. Google does not publish its real sub-searches.

Which payroll software suits a company with 40 staff in Germany?

Google AI

payroll software price per employee
payroll software mini-jobs Germany
payroll software reviews 2026
payroll-one.example/pricing
help.payroll-two.example/mini-jobs
reviews.example/payroll
  1. 1. Payroll One1
  2. 2. Payroll Two2

  1. One question

    The buyer asks one question in plain words.

  2. Several searches

    The AI runs smaller searches: price, fit, reviews.

  3. Pages read

    It reads the pages each search finds.

  4. One answer

    It names companies and links some pages.

One question fans out into three searches. Each search finds a page. The answer names two companies and links their pages.

Example: made-up sub-searches for one buyer question. They show the idea, not Google's real queries.

Why does query fan-out matter for a company?

Each sub-search is a chance for one of your pages to be read. Pages that answer one thing clearly fit best.

  • Give price, fit, setup and proof their own clear sections.
  • Keep key facts on your own site. If a fact is missing, AI may read it elsewhere.

Questions about query fan-out

Does ChatGPT run several searches too?

An OpenAI model did in our runs. It ran 565 searches in 115 runs, about 5 per run. We used Codex CLI, not the ChatGPT app, so the app may differ.

Can I see the sub-searches AI runs?

Google does not show them. Some tools guess them with their own AI model. Treat such lists as ideas, not data.

Is query fan-out the same as keyword research?

No. Keyword research looks at what people type. Fan-out is what the AI types for them, behind the scenes. The two often overlap.

Check the questions your buyers ask

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How to show up in Google AI Overviews

What Google's AI reads, and what you can change.

Sources

  1. Google, AI in Search: Going beyond information to intelligence (Elizabeth Reid, 20.05.2025), checked
  2. Google Search Central, AI features and your website, checked
  3. Nenn, Nenn test: 13 software questions, 115 runs, 366 citations, checked . OpenAI model (gpt-5.6-luna) via Codex CLI with web search, not the ChatGPT app, 01-02.11.2026, 13 software questions.