---
title: "Answer engine optimization (AEO)"
slug: "answer-engine-optimization"
category: "seo"
tags: ["seo", "aeo", "ai-search", "citations", "geo"]
status: "stable"
last_updated: 2026-05-29
summary: "Become the cited answer in ChatGPT, Perplexity, and Gemini by writing extractable claims, surfacing entities, and allowing answer-engine crawlers."
related: ["[[seo/ai-search-optimization]]", "[[seo/ai-overviews]]", "[[seo/llms-txt]]", "[[seo/e-e-a-t]]", "[[seo/structured-data]]", "[[seo/discoverability-files]]", "[[seo/glossary]]", "[[seo/audit-checklist]]"]
---

## Overview

Answer engine optimization (AEO) is the discipline of getting a page quoted as the answer inside a conversational AI engine: ChatGPT search, Perplexity, Claude, and Gemini. AEO is the citation-side sibling of [[seo/ai-overviews]], which targets the Google SERP feature specifically; this page covers the off-Google answer engines. AEO inherits the shared playbook in [[seo/llm-seo-best-practices]] (atomic claims, entity surfacing, discoverability files) and adds the engine-specific rules below. The unit of success is a citation with a link back, not a ranking position.

## Write the answer as the first sentence under a question-shaped heading

Answer engines extract the sentence that most directly answers the user's prompt. Structure each section so that sentence is unmissable.

- Use an H2 or H3 that phrases a real question or task: "What is INP?" "How to set a canonical URL."
- Open with a single declarative sentence that answers it in under 30 words.
- Follow with one specific fact per sentence: a number, a version, a named entity.

Hedged, multi-clause sentences get paraphrased and lose the link. Short declarative sentences get lifted verbatim and keep it.

## Allow the answer-engine crawlers, or there is nothing to cite

A page that blocks the fetcher cannot be quoted. AEO starts with crawler access in `robots.txt`.

- ChatGPT search reads with `OAI-SearchBot`; user-initiated fetches use `ChatGPT-User`. Training uses `GPTBot`.
- Perplexity indexes with `PerplexityBot`; user-initiated fetches use `Perplexity-User`.
- Claude search uses `Claude-SearchBot`; user fetches use `Claude-User`.

Allow the search and user-fetch agents even if you disallow the training agents. See [[seo/discoverability-files]] for the full token catalog and [[seo/answer-first-content]] for the citation-hygiene rules.

## Ground entities so the engine resolves the right thing

Answer engines disambiguate using named entities and their identifiers. Surface them so the model maps your page to the correct concept.

- Name the primary entity in the `<title>`, the `<h1>`, and the first sentence.
- Mark it up with `DefinedTerm` or `Article` JSON-LD, with `sameAs` pointing at the Wikipedia or Wikidata URL.
- Keep one concept per page; a page that defines five things gets skipped for one that defines one.

This is the same entity work that wins [[seo/ai-overviews]]; the markup earns no SERP feature on its own but it grounds the citation.

## Measure citations directly, not through rankings

AEO does not show up in rank trackers. Measure it where the citation appears.

- Run a fixed prompt list weekly through ChatGPT, Perplexity, and Gemini; record which prompts cite the domain.
- Filter server logs for `OAI-SearchBot`, `PerplexityBot`, and `Claude-SearchBot`; a fetch spike usually precedes a citation by 24 to 72 hours.
- Track the link, not the impression. A citation with no click-through link is worth less than a ranked blue link.

## Related

- [[seo/ai-search-optimization]]
- [[seo/ai-overviews]]
- [[seo/llms-txt]]
- [[seo/e-e-a-t]]
- [[seo/structured-data]]
- [[seo/discoverability-files]]
- [[seo/glossary]]
- [[seo/audit-checklist]]