AEO vs GEO vs SEO: Differences, Overlap, Which You Need

SEO optimizes a page to rank as a link in search results. AEO (answer engine optimization) optimizes it so engines like Google AI Overviews or Perplexity can quote a direct answer. GEO (generative engine optimization) optimizes content and entity signals so models like ChatGPT and Gemini mention and cite you in answers. Most businesses need all three.

The three terms describe different outputs rather than rival disciplines, and they share a large common foundation. This guide gives the side-by-side table, the overlap, the places they genuinely diverge, a quick way to choose by situation, and what to ask an agency before you buy any of it. Where a point comes from an engine's own documentation we say so, and where it is our editorial judgment we label it. If you would rather hand the work off, our AI search optimization services cover all three layers and are scoped in writing, but no one can guarantee that a specific engine will quote or cite you.

The one-table answer

• Output you are trying to win

  SEO

  A ranked link in a results list

  AEO

  A direct answer quoted from your page, with attribution

  GEO

  A mention or citation inside a composed, multi-source answer

• Where it shows up

  SEO

  Google, Bing and other classic results pages

  AEO

  Google AI Overviews and AI Mode, Perplexity, ChatGPT search, voice assistants

  GEO

  ChatGPT, Gemini, Claude, Copilot, Perplexity and AI Overviews when they write longer answers about a topic or a brand

• Unit of success

  SEO

  Position and clicks

  AEO

  Your passage is the one extracted and credited

  GEO

  Your brand appears in the answer, described accurately

• Unit of work

  SEO

  The page and the keyword it targets

  AEO

  The question and the passage that answers it

  GEO

  The brand, its facts and the sources that repeat them

• Main levers

  SEO

  Crawlability, relevance, content quality, links, page experience

  AEO

  Answer-first writing, clear headings, content in text, structured data that matches the page, crawler access

  GEO

  Consistent entity facts, third-party coverage, corroborated claims, quotable evidence (editorial judgment)

• How it is measured

  SEO

  Rankings, impressions, clicks and conversions

  AEO

  A fixed question panel: quoted or not, cited or not

  GEO

  The same panel across engines: mentioned or not, described accurately or not, and which sources were cited

• How fast changes show up

  SEO

  Depends on crawl and ranking systems; no published schedule

  AEO

  Crawl-access fixes can register quickly (OpenAI says about 24 hours for its search crawler's robots.txt); wording changes depend on when each engine re-reads the page

  GEO

  Usually the slowest, because it depends on sources outside your site (editorial judgment)

No row in that table is a ranking factor published by an engine. It describes what each discipline aims at and how you would check it.

AEO vs GEO: the pair that gets confused

The easiest way to hold them apart is by the question each one asks. AEO asks whether your page contains an answer an engine can lift and attribute. GEO asks whether your brand shows up, accurately, in the wider set of sources a model reads when it writes a longer answer about you, your category or your competitors. Our guide to what answer engine optimization is covers the page-level work, and the guide to what generative engine optimization is covers the brand-level work and how GEO compares with classic SEO.

A page can be built well for AEO and still be missing from answers if the engine leans on third-party sources instead of your site. We treat them as two layers of one program, with SEO underneath both.

Where they overlap

Most of the work is shared, and it is mostly ordinary SEO. Google's documentation on its AI features is direct about this: a page must be indexed and eligible to be shown in Search with a snippet to appear as a supporting link, there are no additional technical requirements, and no special optimization, AI text files, special markup or special structured data is needed. It also says the best practices for SEO remain relevant for AI features. That makes the shared foundation:

Crawlability and indexing. If Googlebot cannot fetch and index a page, it has no path into AI Overviews or AI Mode. For ChatGPT, OpenAI says OAI-SearchBot is the crawler that surfaces sites in its search features and that a site opted out of it will not appear in ChatGPT search answers, though it can still show up as a navigational link. GPTBot, the training crawler, is a separate setting.

Content in text, with clear structure. Google tells site owners to make important content available as text and to keep structured data consistent with what is visible on the page. That serves classic rankings, answer extraction and synthesis equally.

Authority and entity consistency. The same name, description and key facts, repeated consistently across your site and the places that describe you, help a ranking system, an extraction system and a model decide who you are. This is editorial judgment, not a documented ranking factor.

Freshness and accuracy. Dated, maintained and correct pages are easier for any system to trust (editorial judgment).

One practical consequence: do not build three versions of a page. A single well-built page serves all three. One thing to drop is the old FAQ markup habit. Google's documentation updates say the FAQ rich result stopped appearing in Google Search from May 7, 2026. A visible question-and-answer section is still useful to readers and gives engines clean pairs to read, but the expanding result in Google is gone.

Where they diverge

SEO ranks documents. The system compares pages against a query and orders them. You win by being the best page for that query.

AEO extracts passages. The system pulls a piece of a page to build an answer and credits it. Self-contained passages with the answer up front matter more here than they do for a ranked link. Google also says AI Overviews and AI Mode may use a technique it calls query fan-out, issuing multiple related searches across subtopics and data sources, so a single question can pull in links for several sub-questions, and that the two features may use different models, so the links can differ. Our guide to ranking in Google AI Overviews covers that engine specifically.

GEO shapes synthesis. The system composes an answer from several sources and decides which to mention. Perplexity's help center says it searches the internet in real time, compiles the most relevant information and cites its sources with numbered citations, and that it remembers the context of earlier questions in a conversation, so the same brand can appear in one answer and vanish in the follow-up. Your page is one input among many, and some of the inputs are outside your control. The research that coined the term, published as an arXiv paper in November 2023 and accepted to KDD 2024, reported gains of up to 40% in visibility inside generative answers in its own benchmark and said the effectiveness of its strategies differs by domain. Treat that as a best-case ceiling from a controlled test, not a forecast for your site. Our guide to getting cited by AI covers the practical side.

In short: SEO is about being ranked, AEO about being quoted, and GEO about being included in a summary. A rank tracker checks the first. The other two can only be checked by asking the engines, repeatedly.

What about AIO, LLMO and AI search optimization?

The vocabulary is messy, and it is fair to say no standards body governs it. In our usage, AIO most often means Google's AI Overviews, the answer box at the top of some results, and occasionally gets used as shorthand for AI optimization in general, so check the context. LLMO means large language model optimization and is, in practice, another label for GEO with the model rather than the answer as the object. AI search optimization is the umbrella term for all of it: the SEO foundation, AEO on the page, and GEO across the sources around you. If a vendor pitches AEO, GEO, LLMO and AIO as four products, read the deliverables, because the work overlaps heavily.

Which you need, by situation

Most businesses end up doing all three, so the useful question is where to start. This is editorial judgment, not an engine rule.

• Pages are thin, slow, unindexed or hard to crawl

  Start with

  SEO fundamentals

  Add next

  AEO on your most important pages

• You rank reasonably but your pages bury the answer under long introductions

  Start with

  AEO

  Add next

  GEO

• Your brand is barely mentioned anywhere except your own site

  Start with

  SEO fundamentals plus consistent entity facts

  Add next

  GEO, starting with the third-party sources that describe you

• You are a local or small business with a handful of questions that matter

  Start with

  SEO basics for your services and location

  Add next

  AEO on your service and question pages

• You are a larger organization with many pages and several teams

  Start with

  An SEO and crawl-access audit across the estate

  Add next

  AEO on high-value pages, then GEO, measured on one shared question panel

• AI tools describe you inaccurately rather than ignore you

  Start with

  A reputation fix at the source level, which is a different job from optimization

  Add next

  GEO once the facts are corrected

• Your site blocks crawlers by accident

  Start with

  Fix robots.txt, CDN and firewall rules first

  Add next

  Everything else

Whichever you choose, measure it. Write a fixed list of the questions your customers ask, run them in each engine on a schedule, and record whether you were quoted, mentioned or cited and which sources were used. Answers change between runs, so watch the pattern rather than one result. Google says traffic from pages shown in its AI features is counted in the Web search type in the Search Console Performance report, so it is not separated out, and an answer that names you without a click leaves no trace in analytics. Our guide to monitoring your brand in AI search walks through a fuller method.

How agencies package them

Here is the honest version. Many agencies that sell AEO and many that sell GEO are selling overlapping work under different names, usually some mix of an SEO audit, page rewrites, structured data review, third-party coverage and a monthly question panel. That is fine until the label stands in for a scope.

Ask any provider for a deliverables list in writing, and look for these items: a crawl and indexing check that names the specific bots; the list of questions that will be tracked and who chose them; which pages will be rewritten and which will be new; what third-party sources, if any, will be pursued and how; the raw answers captured each month, not just a score; and a plain statement of what is not promised. Be wary of anyone who guarantees citations or a place in a specific engine, because each engine chooses its own sources and models change. Be wary of a proprietary visibility score with no raw answers behind it, and of any single file or trick sold as the whole fix, since Google says no AI text files or special markup are needed for its AI features.

You rarely need separate agencies for each of the three. The work shares a foundation, and splitting it tends to produce three reports that do not agree. Reputation Resolutions has been in business since 2013, is A+ BBB accredited and a Google Partner, and has clients in 40+ countries. None of that changes the limit above: we can influence the pages and sources an engine reads, and we cannot control what it says.