What is AEO? Answer engine optimization explained
Answer engine optimization (AEO) is the practice of becoming the source an answer engine quotes when it answers a question directly. Answer engines include Google's AI Overviews and AI Mode, ChatGPT, Perplexity, Gemini and Claude. Instead of returning a list of links, they compose an answer and cite a small number of supporting pages. AEO is the work of getting your page into that small set.
How AEO differs from classic SEO
Classic SEO competes for a position on a results page that shows many links. An answer engine changes the economics in two ways:
- An answer cites few sources. Where a traditional results page might list ten or more organic results, a generated answer typically quotes or links only a handful of pages. There is far less room, so the difference between being cited and not being cited is close to binary.
- Position zero economics. The question is often resolved on the results surface itself. The click happens when the reader wants depth, verification or a next step. Being the cited source is what puts your brand in front of the reader at the moment the answer is given, whether or not a click follows.
There is also a difference in granularity. Answer engines quote or paraphrase specific passages, not whole pages. A page can rank well overall and still contribute nothing to an answer if no single passage states the answer plainly.
How AEO overlaps with classic SEO
According to Google's AI features guide, AI Overviews and AI Mode select content using retrieval-augmented generation that is grounded in the core Search ranking systems. In practice that means the entry requirements are the same ones SEO has always had: your content must be indexed, crawlable and eligible to appear as a snippet.
Google is equally clear about what is not required. There is no special markup and no AI-specific file to add. The llms.txt file is ignored by Google Search. Structured data is not required for generative AI features. Google also advises against chunking content or writing in a special format for AI. Good pages for readers are good pages for answer engines.
So AEO is not a replacement discipline. It sits on top of the same crawl, index and rank foundation, and adds a specific question: when an engine assembles an answer, is your page the one worth quoting?
What practically moves AEO
Answerable structure
Write headings that match real questions and answer each one directly in the first sentence or two beneath the heading. A passage that states the answer plainly, then supports it, is easy to retrieve and easy to quote. A passage that circles the answer for three paragraphs is not.
Verifiable claims
Engines assembling an answer favor statements they can attribute. Specific, checkable claims with named sources are more quotable than vague generalities. If you cite a number, link where it comes from.
Freshness
Recency matters, and updating matters more than publishing. A study of 7,683 pages and 47,097 citations found that Gemini cited content updated within the past year 78 percent of the time, ChatGPT 73 percent and Perplexity 65 percent. Yet only 42 percent of the cited content had been recently published. The gap is the lesson: most cited pages were older pages that had been kept current. A maintained article outperforms a stream of new ones.
Being quotable
Each important point should survive being lifted out of context. Self-contained passages, with the subject named rather than referred to as "it", give an engine something it can place directly into an answer with a citation attached.
What to ignore
Skip anything sold as a shortcut into Google's AI results. No third-party tool has access to Google's internal systems, and the official guidance asks for nothing beyond normal, indexable, snippet-eligible content. Be equally careful with citation-tracking claims: single spot checks of an answer engine are unreliable, for reasons covered in how answer engines choose their sources.