What is Answer Engine Optimisation? A Plain-English Field Guide to AEO

If you have spent the last fifteen years optimising for the ten blue links, the new question is short and slightly disconcerting. When a customer asks ChatGPT, Claude or Perplexity a question, does your brand appear in the answer? Not on the second page. Not in a snippet. In the answer.

That question is the whole of Answer Engine Optimisation, usually shortened to AEO. It is the discipline of getting cited, named, quoted or recommended by the systems that increasingly sit between a curious person and the rest of the web.

This guide is a starting point. It is written for marketers, founders and curious technologists who would rather understand the shape of a new field than be sold a tool for it.

A working definition of AEO

Answer Engine Optimisation is the set of practices that influence whether, how and how often an answer engine cites a particular source, brand or product when responding to a user's question.

Three things are doing the work in that sentence.

First, the question is about being cited. Traditional search optimisation is about being ranked. The two are related, but they are not the same. A page can rank tenth on Google and still be the source quoted in a ChatGPT answer. The reverse is also true, more often than people assume.

Second, the actor is an answer engine, not a search engine. The distinction is real even if the line is fuzzy. A search engine returns a list. An answer engine returns a sentence, sometimes with sources, sometimes without. ChatGPT, Claude, Gemini, Perplexity, Grok and DeepSeek are all behaving as answer engines for a growing share of queries, even when they are also doing other things.

Third, AEO is about influence, not control. Nobody outside the model labs can guarantee a citation. The honest claim of an AEO practitioner is that they can shift the odds, not flip a switch.

Why AEO matters now

Three quiet shifts have made AEO worth a line item in a marketing budget.

The first is that AI assistants have moved from novelty to habit. People do not announce that they have changed how they search, but the logs of every analytics tool tell the story. Sessions are shorter. Direct traffic is up. Branded queries have begun to behave oddly. The cause, in many categories, is that the research step now happens inside an AI conversation rather than across ten tabs.

The second is that AI answers tend to be single-winner. A search results page can name fifty businesses. An AI answer typically names two or three, and one of them with confidence. Being the named answer is a different kind of prize from being the seventh listing.

The third is that the inputs have shifted. AI systems are trained on, and at inference time often reference, a much wider lattice of sources than a classical search index ranks. Review sites, structured data, podcast transcripts, Wikipedia, niche industry registers, and even, occasionally, social posts can carry surprising weight. The map of what matters has been redrawn.

What AEO is not

It is worth being clear about a few things AEO is not, because the field has attracted some forceful claims.

AEO is not a guaranteed channel. It is a probabilistic one. A well-optimised brand will be cited more often than a poorly optimised one, on average, over time. That is the honest promise.

AEO is not a replacement for classical SEO. The majority of long-tail intent still passes through traditional search at some point in the journey. AEO sits next to SEO, not on top of it.

AEO is not the same as prompt engineering. Prompt engineering is what a user does to get a better answer from an AI. AEO is what a brand does to influence the answer the user receives.

The four pillars of AEO, briefly

Most useful AEO work today falls into four buckets.

Source quality. Are the pages, profiles and listings that describe the brand factually accurate, structured cleanly, and findable on the open web? An AI system that cannot read or trust a source will not cite it.

Authority signals. Mentions, links, reviews and references from sources that AI systems themselves treat as authoritative. Wikipedia, well-edited industry registers, reputable publications, and trusted review platforms tend to punch above their weight here.

Query coverage. Does the brand's content actually answer the questions a real customer would ask, in roughly the language they would ask them? AI answers favour content that addresses a question directly rather than gestures at it.

Measurement. Without measurement, AEO work is faith. Without good measurement, it is worse than faith; it is faith plus false positives. A serious AEO practice tracks which engines cite the brand for which prompts over time, and how that changes when the brand acts.

A modest beginning

For a brand that has not done any AEO work, the first useful step is also the most uncomfortable one. Ask the six big AI systems thirty of your most important customer questions, and write down what they say. Note when you are cited, when a competitor is cited, when the AI hedges, and when it confidently makes something up about your category.

That document is the baseline. Everything that follows in an AEO programme is an attempt to move the numbers it contains.

We will go deeper on each of these pillars in future articles. For now, the short version is this. Answer Engine Optimisation is not magic, it is not a fad, and it is not, for most brands, optional much longer.

Common questions about AEO

Is AEO the same as GEO? Generative Engine Optimisation is the more common term in some circles, particularly in academic writing. The practical work is essentially the same. We treat AEO and GEO as synonyms throughout this site.

Do I need new content to do AEO, or can I optimise what I have? Both. A meaningful share of early wins comes from cleaning up existing pages, listings and structured data. Net-new content tends to be the second wave.

How long until I see results? Measurable shifts in citation share usually appear within four to eight weeks of meaningful work, assuming you are measuring properly. Anyone who promises faster is probably not measuring properly.

Can my classical SEO agency do AEO? Some can, some cannot. The honest test is whether they can show you a baseline citation report across more than one AI engine, and a plan to improve it. Anything less is rebadged keyword research.