AEO vs GEO vs SEO: what each one is and how they differ

SEO is getting a page ranked in a search engine's results. AEO (answer engine optimization) is formatting it so an engine can extract a direct answer from it. GEO (generative engine optimization) is getting a generative model to choose it as a source when it writes its own answer. They do not compete: all three start from a crawlable, useful, trustworthy page.

To check it on your own site: AI visibility audit

Each one in a sentence

SEO (search engine optimization) is the work of getting a search engine to crawl, understand and show a page in its results, and getting people to click on it. It is the long-standing discipline, with a technical side (crawling, indexing, speed) and a content side. The guide to what SEO is explains it from the ground up.

AEO (answer engine optimization) is the work of making a page contain an answer that an engine can extract and show as it is. Think of a Google featured snippet, a voice assistant's reply or a paragraph an AI assistant lifts whole. What matters is format: the answer at the top, clear headings, lists and tables.

GEO (generative engine optimization) is the work of getting a generative engine, such as ChatGPT search or Perplexity, to use your page as a source when it writes its answer, and to cite it. Unlike AEO, it has a precise origin: an academic paper presented at KDD 2024 that measured which text changes increase that visibility1. What it measured, and its limits, are covered in what is GEO.

The two newer acronyms are the two halves of AI search optimization, the main guide on this topic. In practice they circulate as commercial labels, and nobody has standardised them.

Comparison table: aim, result, signals and measurement

The measurement row causes the most confusion. SEO has official data from the search engine. For the rest, Google says the generative AI performance report in Search Console shows how your content performs in its AI features, and warns that no third-party tool has access to its internal ranking or AI systems2. Other companies' assistants offer no equivalent dashboard: you measure by asking again and again.

What do they have in common?

All three need the page to be crawlable, indexable and understandable. Without that there is no ranking, no snippet and no citation.

Google says so explicitly. Its guide to generative AI features names AEO and GEO and concludes that, from Google Search's perspective, optimising for generative AI search "is optimizing for the search experience, and thus still SEO". It explains that those features are rooted in its core ranking and quality systems and retrieve pages from its index to ground the answer, a technique known as RAG or grounding2. Its documentation on AI Overviews and AI Mode adds that there are no additional requirements to appear in them: the page must be indexed and eligible to be shown with a snippet3.

Outside Google, the principle is the same through a different door. OpenAI says sites that opt out of OAI-SearchBot, its search crawler, will not be shown in ChatGPT search answers, though they can still appear as navigational links4. If the crawler cannot read you, neither format nor sources count.

How do they differ?

The difference lies in what decides the outcome once the page is in contention:

• In SEO, the search engine ranks pages. What matters is that the page is relevant to the query and that the site is technically sound and has authority.
• In AEO, the engine looks for a block that answers. What matters is that the answer sits where it is looked for, at the top, in a format that can be copied without rewriting.
• In GEO, the model chooses between several sources saying similar things. What matters is whatever builds trust: figures with their origin, attributed quotations and who signs the page.

The GEO study illustrates this well. Repeating more words from the query, the classic tactic of old-school SEO, left visibility below the untouched page (17.7 against 19.3 on its main metric). Adding quotations raised it to 27.2, and adding statistics to 25.21. It was a test bench running GPT-3.5, not ChatGPT in 2026, but it points the way: in GEO, verifiable information counts for more than matching words.

One caveat so as not to overstate the difference: Google asks you not to chop up content or rewrite it "just for AI", because its systems understand synonyms and pages covering several topics2. What we call AEO is mostly writing clearly for a reader in a hurry.

One paragraph, optimised for all three

I wrote this example for this article. The workshop and its figures are made up; what matters is what changes in each layer.

Before. At Example Bikes we have spent many years looking after your bike with the very best service and the finest professionals in the trade. We offer all kinds of maintenance services tailored to whatever you need.

After. How long does a full bike service take? At Example Bikes, a full service takes 48 working hours and covers brake and gear adjustment, a drivetrain check and tyre pressures. In 2025 we carried out 1,200 services at our Leeds workshop. Reviewed by Jane Smith, head mechanic, on 7 October 2026.

For the page to work in SEO, it still needs what the paragraph does not show: being indexed, loading fast, and having a title and meta description that match the search. The writing technique step by step, with more examples, is in how to get cited by AI, and author and date signals are covered in E-E-A-T author signals.

How SmoothSeen separates the three

A declaration of interest: this blog belongs to SmoothSeen, a web audit tool that measures visibility in search engines and AI assistants. Its analysis gives two scores from 0 to 100 and keeps them apart because they answer different questions:

AI ranking has two other blocks: Coverage (whether the page resolves the search intent) and what is specific to each page type, such as a product page or a local business. All of it is audited on the page itself; the details are under AI ranking. What it does not do is measure whether Perplexity, Claude or AI Overviews cite you.

Do you need a GEO agency?

Not necessarily, and be wary of anyone promising "rankings in ChatGPT". Google recommends checking any "AEO" or "GEO" advice or service against its guidance on evaluating third-party SEO advice, and warns that no outside tool has access to its internal systems2.

If your technical SEO is in good shape, the AEO and GEO layer is editorial work: answers up front, figures with sources, a visible author and date. Your own team can do it with a checklist. Where an agency adds value is in auditing many pages at once, prioritising and tracking mentions over time.

Frequently asked questions

What does GEO mean in digital marketing?

It depends on the context. In AI search, GEO is generative engine optimization: getting a generative engine such as ChatGPT or Perplexity to use your page as a source. In advertising and analytics, "geo" usually refers to location, as in geotargeting or geofencing. If the text talks about AI assistants, citations or generative engines, it means the former.

Are AEO and GEO the same thing?

No, although they are worked on together and many guides blur them. AEO deals with format: the page has a direct answer that can be extracted. GEO deals with trust: sourced data, attributed quotations and authorship that make a model prefer your page over another one saying the same thing. A page can have one without the other.

Is SEO dead?

No. Google's AI features rely on its index and its ranking systems, and Google itself says optimising for them is still SEO. ChatGPT needs its search crawler to be able to read you. Without crawling, indexing and useful content there is no extractable answer and no possible citation. What changes is that ranking is no longer enough: you also have to be the source that gets chosen.

What do you measure in GEO?

Whether an assistant mentions or cites you when you ask it your customers' questions, and how often over several weeks, because sources rotate a lot. Also the traffic arriving from assistants, which shows up in your analytics tool. And, on your page, the causes: sourced data, attributed quotations, authorship, dates and access for search crawlers.

What to do next

Take your most important page and check the three layers in order: that it is indexed, that the first paragraph answers the question and that its figures carry a source and a byline. The full block-by-block checklist is in the AI search optimization guide.