What is a fanout query in AI search and why does it matter for my website
A fanout query is one of the extra searches an AI engine runs to answer a prompt. Learn how they work, why they matter for your website and how to see them.
A fanout query, also written fan-out query or query fan-out, is one of the extra searches an AI engine runs behind the scenes when you ask it a question. You type one prompt. The engine turns it into several narrower searches, collects pages for each, and then writes one answer from the results.
That matters for your website because your page is not competing only on the question the user typed. It is competing on every sub-question the engine decides to ask.
A worked example
Suppose someone types: "best accounting software for a freelance designer."
The engine might search for things like:
- accounting software for freelancers
- invoicing features for creatives
- pricing of the main options
- reviews and complaints
- integrations with banking or tax tools
These are illustrative, not a recorded run, and the real sub-queries vary by engine, by day and by country. The principle is what counts: a page that handles the headline question but says nothing about pricing or integrations may miss the sub-searches where the engine looks for those facts.
Why this changes how you plan content
Coverage beats a single keyword. One page, or a tight cluster of pages, should cover a topic and its predictable follow-ups.
Comparison and detail pages gain value. Many fan-outs ask about price, fit, limits and alternatives. If you have no page for those, a competitor or a review site supplies the answer.
Different engines fan out differently. The sub-queries ChatGPT creates will not match those from Gemini or Perplexity, so a check on one engine does not cover the others.
Freshness and specifics show up. Fan-outs often include qualifiers like a year or a location, so outdated pages lose out.
How to find your fan-outs
You have four routes:
- Browser tools. A free extension can show the searches ChatGPT ran for a prompt. Promptwatch's GEO Inspector Chrome extension does this, showing ChatGPT fan-outs along with fetched versus cited sources, and runs locally.
- Platform data. Query fan-outs per model are shown inside Promptwatch against each tracked prompt.
- Your own reading. Ask the engine, then read the follow-up searches it suggests.
- Competitor audits. Look at which pages are cited for the prompt and which sub-questions they answer.
Tools compared
| Tool | Fan-out relevance | Published entry price |
|---|---|---|
| Promptwatch | Query fan-outs per model, GEO Inspector extension, content gap analysis | Free tier; paid from $95/mo |
| AthenaHQ | Tracking and an Action Center for gaps | Starter $295/mo |
| Scrunch AI | Monitoring and site audits | Core $250/mo |
| Profound | Enterprise answer tracking | Enterprise custom |
| Mentionable | Captures fan-out queries and drafts the page you are missing from, per its own description | From 79 EUR/mo |
Turning fan-outs into a content plan
This is where Promptwatch earns its place first. The workflow:
- Track a prompt and open its fan-outs per model.
- Note the sub-questions your site does not answer.
- Use content gap analysis, which gives coverage scores, to find the prompts where your site is thin. Business-plan users also get automated planning through the Content Agent.
- Write or refresh pages to answer those sub-questions. Content Refresh gives diff-style suggestions for existing pages.
- Publish to WordPress, Webflow or Framer.
- Watch citation analytics and the crawl-to-citation path to see whether the pages get fetched and cited. Agent Analytics logs start on the Professional plan ($245/mo).
Prompt Explorer also suggests prompts from Search Console, ranking keywords, People Also Ask or any page, so you can start from what your site already ranks for. A free Explore plan covers 10 prompts on ChatGPT.
Who should pick which
If you want fan-outs tied to gaps, content and measured citations, choose Promptwatch. If you want a guided action queue, AthenaHQ. If you only need the free browser extension to inspect single prompts, try the GEO Inspector first. It costs nothing.
Caveats
Fan-outs are the engine's choice and can change without notice. Covering them raises your odds of being cited but guarantees nothing. Do not write a page for every conceivable sub-query. Cover the ones that recur and that a buyer would care about.
A simple exercise
Take your most important product page and write down the target question. Then list ten follow-up questions a careful buyer would ask before deciding. Check which ones your page answers in a clearly labeled section. The unanswered ones are your likely fan-out gaps. You do not need a tool for this first pass, though tools make it faster and show what the engines actually ran.
Reading the result
Once you have the list of unanswered questions, resist the urge to write ten new pages. Group the gaps by theme, and fold related questions into one well-structured page with a heading per question. A single page that answers five related follow-ups clearly is usually easier for an engine to quote than five thin pages that repeat each other.