GEO vs SEO vs AEO: the differences

What is SEO?

Search engine optimization is the work that gets a page crawled, indexed and ranked for the queries people type into a search engine, Google above all. The unit of success is a position in a list: first, third, page two. It is measured in Search Console and rank trackers, and it depends on crawlability, relevance, links and the quality signals Google describes in its helpful content guidance: original information, clear sourcing, a visible author and a reason for the page to exist beyond ranking.

SEO has not gone anywhere. The AI engines read the same web. In our measurements the sources they cite most are Reddit, Wikipedia, TripAdvisor, YouTube and LinkedIn, pages that rank because they are crawlable and trusted.

What is GEO?

Generative engine optimization is the work that gets a business named, and ideally recommended, inside an answer written by a generative engine: ChatGPT, Gemini, Claude, Perplexity or Google AI Overviews. The term comes from a 2023 paper by Pranjal Aggarwal and colleagues, presented at KDD 2024, which measured how edits to a page change its visibility in generated answers.

The unit of success is not a rank. It is whether the answer says your name, where in the list it puts you, whether it calls you the recommendation, and which sources it leaned on. That has to be measured by asking the engines the questions buyers ask and reading every answer, because there is no console that reports it.

The gap between the first two numbers is the whole point of GEO: being known to the engine is not the same as being chosen by it. The third number says where the engines look instead: at third-party pages, not at you.

What is AEO?

Answer engine optimization is the older of the two terms. It started with featured snippets and voice assistants, where an engine returns one answer instead of ten links, and it asks a narrower question than GEO: is your page the answer? The unit of success is the answer box, the voice reply, or the cited passage in an AI response.

The work is the same shape as good writing: one question per page, the answer in the first sentences, evidence after it, headings that read as the questions people ask. Google's helpful content guidance describes the same page, and so does the GEO paper.

What is AIO?

AIO is used for two things, which is why it confuses. Most often it means Google AI Overviews, the generated summary Google shows above the results for many queries. Sometimes it means "AI optimization", a catch-all for GEO and AEO together. On this page it means AI Overviews.

There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary. You don't need to create new machine readable files, AI text files, or markup to appear in these features.

Google Search Central, AI features and your website

So AI Overviews is reached through SEO, and what it says about you is a GEO question. In our data it is the engine most likely to name a business (42.4% of answers) and least likely to recommend one (12.7%): it lists, it rarely picks.

GEO vs SEO vs AEO, side by side

The three share one input, your site and what the web says about you. They differ in where the result appears and how it is counted.

GEO vs SEO: what changes

Three things change when the result is a generated answer instead of a list.

The answer has no page two. A list gives ten businesses a chance; an answer names a few. In our sample an answer that names brands names 7 of them on average, and when a business is named it is first in 45% of those answers. Being tenth in a generated answer does not exist.

The engines read different sources. The 2026 citation studies put the overlap between what ChatGPT and Perplexity cite at about 11% of domains, and Ahrefs found that only 12% of URLs cited by AI tools sit in Google's top ten. Our own numbers agree: for any pair of the five engines, 9 to 17% of the domains either one cites are cited by both. Ranking on Google is not the same as being read by ChatGPT.

You cannot see it in a console. There is no Search Console for ChatGPT. The only way to know what the engines say is to ask them the questions your buyers ask, on a schedule, and read the answers. That is what GEO tools do, and it is the part of the work SEO never needed.

AEO vs SEO: what changes

AEO is SEO with a narrower target. SEO wants a page to rank for a topic; AEO wants a page to be the one answer to a question. The page is the same page, written more plainly: the question in the heading, the answer in the first sentence, the evidence after it. Google's own guidance for helpful content describes exactly that page, which is why AEO rarely needs anything SEO would not.

The difference is in what you measure. A page can rank third and never be the snippet; a page can be the snippet and send fewer clicks, because the question was answered on the results page. AEO counts answers given, not visits earned.

GEO vs AEO: the overlap

Most of the work is shared, and the names are often used for the same thing. The useful distinction is the question each one asks of an answer:

• AEO: did the engine use my page as the answer? (a citation)
• GEO: did the engine name and recommend my business? (a mention)

They come apart in the data. A business is named in 35.2% of the answers we measure, but its own site is cited as a source in 0.6%. The engines build their answers from third-party pages, then name the business those pages talk about. For most businesses that makes GEO the number to watch, and the pages that drive it are not their own.

Do the engines agree with each other?

Rarely, and this is the strongest argument for measuring all of them. We asked the same buyer question to several engines on the same day, 1,351 times, and compared the brands they named.

Same question, same business, same day. Pairs where both engines named at least one brand.

Of the 1,351 questions asked to four or more engines on the same day, 53% ended with no engine recommending the business, 20% with one, and 8% with four or more. A business that checks one engine sees one fifth of the picture.

Which one does your business need?

All three, but not at once, and not in equal measure.

1. SEO first, as a floor. A page that cannot be crawled cannot be cited by anything. Google says the AI features need the standard fundamentals and nothing more.
2. GEO as the number you report. Named, position, recommended, per engine, per question, over time. It is the number that moves when a buyer asks AI who to call.
3. AEO as the writing discipline. One question per page, the answer first, the evidence after. It serves the snippets, the voice assistants and the AI citations at once.

If you sell to people who ask AI for recommendations, start by measuring GEO: ask the engines the five questions your buyers ask, and read what comes back. The free audit on this site does that for three engines and emails the answers. Run it here.