What is AEO? Answer engine optimisation, and why it is just SEO done properly

What does AEO stand for?

AEO stands for answer engine optimisation. An answer engine is any system that replies to a question with a written answer instead of a list of links: ChatGPT, Google's AI Overviews and AI Mode, Perplexity, Microsoft Copilot, Gemini and Claude. AEO is the practice of making your pages the ones those systems read, trust and quote.

Two notes on the name. In the UK, AEO also means Authorised Economic Operator, a customs status, so some searches for the acronym land on shipping pages. This article is about search. And you will see the same job sold as GEO, LLM SEO and AI SEO. They are labels for one activity, and the table below sorts them out.

Is AEO different from SEO?

Not in any way that justifies a separate service. Google's documentation says "There are no additional requirements to appear in AI Overviews or AI Mode", and that the best practices for SEO remain relevant to them. A page that is indexed, clear and trusted is eligible for both. AEO is SEO with the emphasis moved, not a second discipline.

The reason is simple. Every answer engine has to settle three questions about a page before it quotes it. Can I reach it? Do I know who is behind it, and does anyone else vouch for them? Can I lift a sentence from it that is true and complete on its own?

Those are the questions search engines have always asked, in the same order. Reaching the page is technical SEO. Knowing who is behind it, and who vouches for them, is what SEO calls authority. A sentence that is true on its own is simply good content.

What has changed is the price of getting them wrong. A search engine would show a weak page at position nine and let the reader decide. An answer engine names two or three sources and drops the rest, so a page that is vague, unreachable or unvouched-for does not appear at all. Search used to forgive thin pages. Answers do not. That is the whole shift, and it is why SEO done properly and AEO are now the same job.

What is the difference between AEO, GEO, LLM SEO and AI SEO?

They are four names for one activity: getting a business named in answers written by AI. Vendors draw lines between them, but none of the lines is a standard, and the work does not change with the label. If a provider insists they are different products, ask what you would be doing differently on the page.

How do answer engines decide what to quote?

In two stages. First comes retrieval, where the engine assembles a pool of candidate pages from an index or a live search. Then comes selection, where it writes an answer from that pool and favours pages that state something specific it can lift cleanly. A page that is not in the pool cannot be quoted, however well it is written.

Each engine builds its pool differently, which is why "optimise for AI" is not one job:

• Google AI Overviews and AI Mode. Google says a page must be indexed and eligible to be shown in Search with a snippet before it can appear as a supporting link. Ordinary Google indexation is the gate.
• ChatGPT. OpenAI says sites that opt out of its search crawler, OAI-SearchBot, will not be shown in ChatGPT search answers, and recommends allowing it. ChatGPT is also widely reported to lean on Bing's index. OpenAI does not publish that detail, so treat it as a strong hint rather than a fact, and check Bing anyway.
• Copilot. Microsoft's own assistant, built on Bing.
• Perplexity. Its own crawler plus a live search on each question, so fresh pages matter more there.

The second stage is where writing matters. An engine reading ten pages about the same question prefers the one that gives a figure, a place, a limit or a named source, because those can be checked and quoted. Pages that circle a subject for eight hundred words give it nothing to say about you, so it quotes somebody else.

What does the research say actually works?

The best controlled evidence so far is the GEO study from researchers at Princeton and IIT Delhi, presented at KDD 2024. They tested nine ways of rewriting a page and measured how much of an AI-generated answer came from it.

Citing credible sources, adding statistics and adding quotations each raised visibility by roughly 30 to 40%. Writing in plainer, more fluent prose added 15 to 30%. Two things did close to nothing: a more confident, authoritative tone, and repeating the keyword. The second was the core tactic of a generation of SEO.

The finding that matters most to a small business is who gained. Pages ranked lowest in classic search gained the most. In the study, the source ranked fifth gained 115% from citing sources, while the source ranked first lost 30%. Engines that read the page rather than counting links give a young site a chance an old one does not have.

Keep the caveat in the same breath. It is one study, run in 2024 on one engine configuration, and it is not a forecast for any particular site. Read it as a direction: evidence beats tone.

What should I actually do about AEO?

In this order, because the cheap steps come first and are the ones most often skipped:

1. Check Bing. Submit the site to Bing Webmaster Tools. It is free, takes about ten minutes, and a site can rank on Google and still be missing from Bing.
2. Check robots.txt. A single leftover "Disallow: /" from a staging site blocks every crawler without its own rule. OpenAI separates GPTBot, which gathers training data, from OAI-SearchBot, which powers search. You can block the first and allow the second.
3. Search for your own business name. If nothing comes back except your own website, no engine has anything to corroborate. Fix that with your Google Business Profile, the real directories for your trade, and local press, all with the same name, address and phone number. Our local SEO checklist covers the detail.
4. Answer first. Under each heading, give the answer in the first 40 to 60 words, in a paragraph that still makes sense when read alone.
5. Publish numbers and name sources. A price, a place, a timescale, a regulator. These are the checkable facts engines quote, and the ones the study rewarded.
6. Write plainly. Short sentences, one idea to a paragraph, active voice.
7. Keep structured data honest. It should describe what is visibly on the page and nothing more.

Almost none of that is new. Most of it is the list a good SEO would have given you in 2019. What is new is that skipping it is now fatal rather than expensive. Our wider guide to getting recommended by ChatGPT and AI search goes further on each step.

Does llms.txt work?

There is no good evidence that it does. Google's guidance says you do not need new machine-readable files, AI text files or markup to appear in its AI features, and none of the other engines we know of has confirmed that it reads one. We publish one for this site because it takes twenty minutes and forces you to state your facts in one place. Treat it as housekeeping, not a lever, and be wary of anyone who sells it as one.

Does schema or FAQ markup help?

It helps a machine read the page without guessing, which is worth doing. It is not a switch. Google says there is no special schema.org markup you need for AI features, and advises that structured data match the visible text. FAQ rich results have also been limited to government and health sites since 2023, so markup alone will not buy you anything on a commercial site. The questions and answers still need to be on the page, in words a person can read.

Is SEO dead because of AI search?

No. Google says the fundamentals continue to be worthwhile, and an AI answer that links to your site still needs your page to be indexed first. What has died is SEO as a bag of tricks: the repeated keyword, the bought link, the confident paragraph that says nothing. Those never earned trust from a reader, and they earn nothing from a machine that reads the page.

Can anyone guarantee that ChatGPT will recommend my business?

No. There is no ranking to buy and no form to submit, and the answer differs between users and between sessions. Anyone offering a guaranteed position is describing something that does not exist. What you can do is remove the reasons not to name you: be reachable, be corroborated, and say something specific that can be lifted. That moves the odds. It does not fix the result.

How can I check whether AI is recommending my business?

Do it by hand, because there is no reliable rank tracker for answers. Write the ten questions a customer would ask before hiring you. Put each into ChatGPT, Gemini, Perplexity, Copilot and Google's AI Mode, in a fresh session. Write down which businesses are named and which sources are cited. Repeat monthly, because the answers move.

That sample is not a ranking report, but it shows which gate you are failing: whether you are missing from the pool, or in it and passed over. Our SEO audit includes this check.

Do I need to pay for AEO?

Usually not as a separate line, because most of it is search work you would want anyway. With us it is included in every search engagement at no extra charge: the audit is normally £495 and free until 31 December 2026, local SEO is from £695 a month, and a full programme is from £995 a month, with no minimum term. Prices are on the price list. If you are weighing up providers, how to choose an AI SEO agency lists what to ask anyone selling it on its own.

So what is AEO, really?

For about ten years it was possible to rank on Google without being any of the things an answer engine needs. A page could be vague, thinly backed and written for a keyword, and still sit on page one because enough links pointed at it. The answer engines took that shortcut away. They have to say something, and they can only say what a page states clearly and other sources support.

That is why AEO feels like a new subject and is not one. It is the old standard, finally enforced: be reachable, be real, be specific, and be vouched for. If your site already does that, you are most of the way there. If it does not, AI search optimisation is where we would start, and the reasons a site is not ranking are usually the same reasons it is not being named.

Questions about AEO

What does AEO stand for?

AEO stands for answer engine optimisation: making a page easy for ChatGPT, Google's AI Overviews, Perplexity and Copilot to find, trust and quote when someone asks a question. In the UK it is also the acronym for Authorised Economic Operator, a customs status, which is a different subject.

Is AEO the same as GEO?

In practice, yes. AEO, GEO, LLM SEO and AI SEO are different names for the work of getting a business named in answers written by AI. Providers draw distinctions between them, but none is a recognised standard, and the work on the page is the same.

Do I need AEO as well as SEO?

Not as a separate service. Google says the best practices for SEO remain relevant to its AI features, and the same groundwork serves both: crawlable pages, consistent listings, clear writing and references from other sites. Treat AEO as part of doing SEO properly.

Should I block GPTBot?

That is your decision, and it is separate from search visibility. OpenAI uses GPTBot to gather training data and OAI-SearchBot to power ChatGPT search. Blocking GPTBot asks that your content is not used for training. Blocking OAI-SearchBot removes you from ChatGPT search answers.

How long does AEO take to work?

Nobody can give an honest number. Getting indexed in Bing and unblocking crawlers can take effect within days. Building mentions on other sites takes months, and the answers differ between users and sessions. Anyone promising a timescale or a guaranteed mention is describing something that does not exist.