2026-09-03 · 4 min read
GEO, AEO, LLM SEO, AI SEO: do they all mean the same thing?
Four acronyms for one subject, with real but minor differences. What each one means, where it came from, and which to use depending on who you are talking to.
You have met all four in a week: GEO, AEO, LLM SEO, AI SEO. One vendor explained they are different. Another used all four in the same paragraph.
Short answer: yes, it is the same subject — appearing inside the answers written by AIs. The distinctions exist, they are real, and they are minor. Here is the map, so you can read a quote without wondering whether you are being sold four services.
The four terms, one line each
| Acronym | Expanded | What the word emphasises |
|---|---|---|
| GEO | Generative Engine Optimization | the engine generates text instead of listing |
| AEO | Answer Engine Optimization | the engine answers instead of proposing |
| LLM SEO | Large Language Model SEO | a language model is what decides |
| AI SEO / AI search optimization | — | the plain-English phrasing, no acronym |
Four angles on the same object. None describes a method different from the others.
Where each came from
AEO is the oldest. It appeared with Google's featured snippets and voice assistants, well before ChatGPT: the idea was already to be the answer rather than a result. The term was recycled for generative AI.
GEO was born with them, around 2023-2024, popularised by an academic paper of the same name. It is the term the discipline organised itself under: it is what agencies, tools and job listings use.
LLM SEO is the technical practitioners' term: it stresses that the final decider is a model, not a ranking algorithm.
AI SEO and AI search optimization are the spontaneous plain-language formulations. It is what executives who do not know the acronyms type — and often the most honest term to use in a sales conversation.
The one distinction with a practical consequence
If you want to be rigorous, there is one, and only one.
AEO also covers non-generative answers: Google's direct answer box, a voice assistant reading a sentence, a "position zero". There, the engine extracts an existing passage without writing anything.
GEO covers written answers: the engine reads several sources and composes new text. That is what ChatGPT, Perplexity, Claude and AI Overviews do.
The practical consequence: in strict AEO, you optimise a passage so it gets extracted verbatim. In GEO, you cannot target a passage, because the final text does not exist anywhere before it is written. You target something else: being named in the sources the model is going to read.
That is the only difference that changes what you do on Monday morning. Everything else is vocabulary.
What is identical in all four cases
- The central rule. The engine reads three to eight pages before answering. If none of them names you, you do not appear — however good your site is.
- The dominant lever. Being present on the sources the engine reads in your market: trade directories, comparison sites, review sites, specialist press, forums, local bodies. Our public measurements show it sector after sector: the most-cited name among Normandy campsites is a tourist board, not a campsite. The study.
- The measurement problem. A model is not deterministic. A question asked once proves nothing, whatever acronym is on the invoice. Why.
- The absence of position. You are cited or you are not. There is nothing to follow in a rank tracker.
Which one to use
- To find a vendor or a tool: GEO. That is the term the market organised itself under.
- To talk to your board: AI search optimization. Everyone understands, nobody asks what the acronym means.
- To read a quote: the word used does not matter. Ask these four questions instead: how many questions, how many passes each, which assistants, and are the consulted sources returned. The detail of those questions.
The real warning sign
A vendor selling you GEO and AEO as two separate services, with two budgets, is selling vocabulary. They are two angles on the same work: identify the sources read in your market, exist on them, and write quotable facts.
If you would rather start by knowing where you stand than by buying a plan: our GEO audit measures 40 questions from your market across three assistants, three times each — 360 measurements, report within 48 hours, €149 excl. VAT.
For the underlying subject, the complete GEO guide.