Answer engine optimization (AEO) is the work of making a brand's pages and facts easy for AI answer engines to find, trust and reuse, so that the brand is named or cited when those engines answer a question. An answer engine replies with a direct answer instead of a list of links to sift through, which is how Perplexity's help center defines the term.
The seven engines in our scans (how we measured) all work this way: ChatGPT, Perplexity, Gemini, Claude, Grok, Google AI Overviews and Google AI Mode. All seven showed links to their sources in their answers.
How AEO works
An engine that searches the web finds pages, writes an answer from them and shows some of those pages as citations. AEO work falls into three matching parts.
- Access. The engine has to be able to reach the page. OpenAI says sites that opt out of its OAI-SearchBot crawler are not shown in ChatGPT search answers, apart from navigational links. Google requires a page to be indexed and eligible for a snippet before it can be a supporting link in AI Overviews or AI Mode. What an AI crawler is covers the bots involved.
- Answer-shaped pages. A page states the question a buyer asks and answers it plainly, near the top.
- Presence on other people's pages. In our scans, "best tools" and "alternatives" roundups took 52.5 percent of the citations that went to the 100 most-cited sites, which is why getting into roundups is part of the job.
Why AEO matters
The audience is large. In 2026, Google said AI Overviews had over 2.5 billion monthly active users and AI Mode more than 1 billion monthly users.
The engines also read different parts of the web. In our scans, ChatGPT's five most-cited sites and Grok's five most-cited sites had nothing in common, so a brand can be visible in one engine and missing from another. The full comparison is in what seven AI engines cite.
An example: a page built around one question
Cituna, the AI visibility tool this publication's team builds, has a guide whose headline is a buyer's literal question: "Which AI Visibility Tool Includes Google Search Console?" The same question is one of the prompts in our scans. In the 30 days to 22 September 2026, ChatGPT cited that page 10 times and Gemini 11 times.
It is one page and one question, so read it as an illustration of the method, not proof that question headlines always win. How to write content that AI engines cite covers the pattern in more depth.
Common misconceptions
- "AEO replaces SEO." For its own AI features, Google says the reverse. Its guide to generative AI features, last updated 10 July 2026, says that from Google Search's point of view, optimizing for generative AI search is still SEO, and that SEO best practices stay relevant because those features are rooted in its core ranking and quality systems. AEO vs GEO vs SEO sets out where the three overlap.
- "AEO needs special files or markup." Google says its AI features need no llms.txt file, AI text file, special schema or content cut into small chunks.
- "AEO and GEO are different disciplines." Google's guide describes both as terms for work aimed at visibility in AI search. GEO began as a research term; see generative engine optimization.
- "One score shows how you are doing." Visibility differs by engine, as the ChatGPT and Grok lists show, so measure each engine on its own.