GEO, AEO, LLMO:what the termsreally mean
Four acronyms, one goal: being named in the answers of ChatGPT, Gemini, Perplexity and Google. Where the terms come from, where they differ and what counts for your business.
Get in touch- What do GEO, AEO and LLMO mean?
- Where does the term generative engine optimization come from?
- What is AEO, and how is it different from GEO?
- LLMO and LLM SEO: a discipline of its own or a new label?
- What does AIO mean, and why is the acronym ambiguous?
- GEO vs AEO vs LLMO vs AIO side by side
- Does GEO need special files or schema markup?
- Which term matters for your business?
- Frequently asked questions
- How to find out where your company stands in AI answers
- Where the information on this page comes from

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Check your AI visibility or call: +49 151 1576 5566GEO (generative engine optimization), AEO (answer engine optimization), LLMO (large language model optimization) and AIO describe the same goal from slightly different angles: your brand should appear in AI answers, and it should be described correctly. Only GEO has a traceable origin, a research paper from 2023. AEO grew out of answer boxes and voice assistants, while LLMO and AIO are industry labels without a fixed definition. So the acronym is not what matters for your business. What matters is a question you can measure: are you named when customers ask an AI for a solution like yours?
- GEO goes back to a research paper published in 2023 and presented at the KDD conference in 2024.
- AEO is older and aims at the single direct answer delivered by answer boxes and voice assistants.
- LLMO, LLM SEO and AIO are industry terms without an agreed definition; AIO often simply means Google's AI Overviews.
- What counts is whether and how AI systems mention your company, and that can be measured.
On this page
- What do GEO, AEO and LLMO mean?
- Where does the term generative engine optimization come from?
- What is AEO, and how is it different from GEO?
- LLMO and LLM SEO: a discipline of its own or a new label?
- What does AIO mean, and why is the acronym ambiguous?
- GEO vs AEO vs LLMO vs AIO side by side
- Does GEO need special files or schema markup?
- Which term matters for your business?
- Frequently asked questions
- How to find out where your company stands in AI answers
- Where the information on this page comes from
What do GEO, AEO and LLMO mean?
All three acronyms describe work on content that helps AI systems find a brand, understand it and use it in their answers. The differences lie mainly in which kind of system they have in mind and when the term came up.
GEO, generative engine optimization, is about generative search: services that pull together several sources for a question and write their own answer from them. Think of search in ChatGPT, Perplexity and the AI answers in Google.
AEO, answer engine optimization, targets the direct answer to a clearly phrased question. The term predates today's chatbots and comes from work on answer boxes in Google Search and on voice assistants.
LLMO, large language model optimization, often called LLM SEO, puts the language model itself at the centre: how does a model read your content, and what does it say about you in a chat? AIO means either artificial intelligence optimization or Google's AI Overviews, depending on who is talking. More on that below.
One thing to keep in mind: there is no generally accepted line between these terms. The Wikipedia article on GEO notes that no consensus definition had been established in the academic literature as of early 2026 and that the terms are often used interchangeably. Industry guides from IONOS and Evergreen Media likewise describe the field as young and inconsistently named.
Where does the term generative engine optimization come from?
GEO is the only one of the four terms with a clearly datable origin. In November 2023 a team from Princeton University and the Indian Institute of Technology Delhi published the paper “GEO: Generative Engine Optimization” on the preprint server arXiv. In August 2024 it was presented at KDD, a major data mining conference.
For the study the researchers built a benchmark called GEO-bench with around 10,000 queries from many subject areas. They rewrote web content following different patterns and measured how much of it then showed up in the answers of a generative search system. According to the paper's abstract, visibility rose by up to 40 per cent. The findings were also checked against Perplexity, a publicly used system.
Three patterns worked best: citing sources, adding direct quotations and replacing vague claims with concrete figures. Classic keyword stuffing, repeating a search term over and over, brought little to no improvement. That is the real takeaway for practice: what an AI likes to cite looks more like a well-sourced trade article than a page tuned for keywords.
One caveat belongs here. The paper measures under lab conditions, research has moved quickly since, and the gains vary by subject area. The study shows a direction, not a guarantee for any single page.
more visibility in generative answers was the best case the researchers reached with deliberately revised content.
What is AEO, and how is it different from GEO?
Answer engine optimization comes from SEO practice, not from research. The groundwork was laid by featured snippets in Google Search, around since about 2014, and by voice assistants that read out exactly one answer to a question. The term has been in wide use since 2024 and 2025, when AI answers in search became part of everyday life.
The difference from GEO is one of scope. AEO thinks in single questions and short, self-contained answers: what is it, how does it work, roughly what does it cost. GEO thinks in composed answers, where a system weighs several sources and combines them into a new text. Doing well at AEO means writing clear answer paragraphs. Doing well at GEO means also supplying evidence an AI can rely on.
In practice the two complement each other. A page with a clear answer at the top, question-style subheadings and sourced figures meets the demands of both schools at once. This article is built exactly that way.
LLMO and LLM SEO: a discipline of its own or a new label?
LLMO shifts the focus from the search system to the language model. IONOS describes LLMO as structuring and writing content so that large language models can understand, reuse and reference it. Evergreen Media uses it for everything that improves how a brand appears in chatbots such as ChatGPT, Gemini or Claude, and lists GEO, AEO and AIO as related labels.
That makes LLMO a working term rather than a standard. Both sources treat it as a label in a field that is still sorting itself out. LLM SEO is another, equally loose name from the same practice.
From our own work comes a distinction that matters in practice: a language model can talk about you in two ways. Either from what it learned in training, or from pages it searches live on the web while answering. That is why our AI visibility analysis records whether a system answered with or without web search. The results can differ considerably, and only the second route can be influenced in the short term through your website and through mentions on other sites.
What does AIO mean, and why is the acronym ambiguous?
AIO is used in two senses, which regularly causes confusion. In one it stands for artificial intelligence optimization, an umbrella term for optimizing for AI systems; Evergreen Media, for instance, lists it next to GEO and AEO. In the other, AIO is simply short for Google's AI Overviews, the AI summaries above the search results; the US agency OuterBox uses it that way, for example.
So if someone offers you “AIO”, it pays to ask: are we talking about all AI systems or only Google's AI Overviews? How to appear in Google's AI summaries is covered in our article on Google AI Overviews. ChatGPT in particular is the topic of ChatGPT SEO.
GEO vs AEO vs LLMO vs AIO side by side
The table sums up what the acronyms stand for, where they come from and what they aim at. Treat the split as orientation, not a standard, because binding definitions do not exist yet.
| Term | Stands for | Origin | What it aims at |
|---|---|---|---|
| GEO | Generative engine optimization | Research paper, arXiv 2023, KDD 2024 | Being used as a source in composed AI answers |
| AEO | Answer engine optimization | SEO practice, featured snippets and voice assistants | Delivering the one direct answer to a clear question |
| LLMO / LLM SEO | Large language model optimization | Industry practice, no fixed definition | How language models read content and repeat it in chat |
| AIO | Artificial intelligence optimization or AI Overviews | Industry practice, two meanings | Umbrella term for AI optimization, or Google's AI Overviews only |
| SEO | Search engine optimization | Classic search optimization | Ranking well in search results, the basis for all the others |
Does GEO need special files or schema markup?
The official documentation helps here. In its guide to AI features, Google states that there are no additional requirements and no special optimizations needed to appear in AI Overviews or AI Mode. New machine-readable files, AI text files or special schema.org structured data are not required. Existing SEO best practices remain relevant.
That does not make structured data useless: it helps classic search understand your content and does no harm. It does mean nobody can promise you a place in Google's AI answers on the strength of one technical feature. What the proposed llms.txt file is about is explained in our article on llms.txt.
Other providers such as OpenAI or Anthropic offer no comparably detailed guidance. That is why we prefer measuring to guessing: which pages a system actually cites is visible in the answer itself.
Which term matters for your business?
Honestly, none of them. A buyer asking an AI for a supplier does not care which acronym you file your content under. What counts for you is whether your company appears in the answer, in what position, in what tone and with correct details. That can be measured, whether your provider calls it GEO, AEO or AI SEO. For an overview of the work on your own website, see our article on AI SEO.
In our AI visibility analysis we put questions to several AI systems the way real customers would ask them, in four forms: the recommendation question asking for a suitable solution, the problem question in everyday language, the scenario from the point of view of a role in a company, and the specialist question about a standard or specification. For technical suppliers the last one often separates the leaders from the rest.
We evaluate along a few clear metrics: how often are you named compared with competitors? Are you merely mentioned or cited as a source? Are the facts about your company right? In what tone does the AI talk about you, and where do you sit in a list of recommendations? How this works in detail is shown in Measure AI visibility.
One observation from our audits that matches the GEO research: your own website is only one of many sources. A machine builder with an excellent product page can still be missing from AI answers if trade media, directories and industry portals do not mention it. That is why our GEO audit always covers both sides: your own content and the mentions on other people's sites.
- 01
Measure
Step 1Put customer-style questions to several AI systems and record who gets named.
- 02
Assess
Step 2Evaluate mentions, citations, accuracy and tone against competitors.
- 03
Improve
Step 3Revise your content with clear answers, figures and sources, and build mentions on third-party sites.
- 04
Repeat
Step 4Measure again at fixed intervals, because AI answers keep changing.
Frequently asked questions
Is GEO the same as SEO?
No, but it builds on it. SEO aims at good rankings in search results, GEO at appearing as a source in AI-generated answers. Google itself says SEO fundamentals also apply to its AI features.
Who coined the term GEO?
A research team from Princeton University and IIT Delhi, with the paper “GEO: Generative Engine Optimization”, published on arXiv in November 2023 and presented at the KDD conference in August 2024.
What is the difference between GEO and AEO?
AEO targets the single direct answer to a clear question, as delivered by featured snippets and voice assistants. GEO targets answers that an AI system composes from several sources. Clear answer paragraphs help both; evidence and figures help GEO in particular.
What does LLMO mean?
LLMO stands for large language model optimization and describes content that language models can understand and repeat well. There is no binding definition; LLM SEO is another label from the same practice.
Does AIO mean AI optimization or AI Overviews?
Both, depending on who uses it. Some mean artificial intelligence optimization as an umbrella term, others Google's AI Overviews. If in doubt, ask which systems are meant.
Can an agency guarantee the top spot in ChatGPT?
No. AI answers change with the question, the system and the moment. A serious approach measures visibility, improves it deliberately and measures again at regular intervals.
How to find out where your company stands in AI answers
- 01
Collect questions
Write down ten questions your customers would ask an AI, from recommendations to specialist questions.
- 02
Test it yourself
Ask these questions in ChatGPT, Gemini, Perplexity and Google Search and note who gets named.
- 03
Name the gaps
Record where you are missing, described wrongly or only appear behind competitors.
- 04
Measure systematically
Have your visibility measured with a fixed method so you can prove improvements. More on our GEO agency page, training for your team under AI training.
The acronyms change, the question stays: does the AI name your company when customers look for a solution, and is what it says about you correct?
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Where the information on this page comes from
- Aggarwal et al.: GEO: Generative Engine Optimization (arXiv)accessed 25 Sep 2026
- GEO: Generative Engine Optimization, full text v3 (arXiv)accessed 25 Sep 2026
- Princeton University: publication record GEO, KDD 2024accessed 25 Sep 2026
- The GEO Community: The Original GEO Paper explainedaccessed 25 Sep 2026
- Google Search Central: AI features and your websiteaccessed 25 Sep 2026
- vrid.ai: Structured data needed for AI search? Google answersaccessed 25 Sep 2026
- AI Search Glossary: Answer Engine Optimizationaccessed 25 Sep 2026
- Stackmatix: The Complete History of AEOaccessed 25 Sep 2026
- IONOS Digital Guide: Large language model optimizationaccessed 25 Sep 2026
- Evergreen Media: Large Language Model Optimization explainedaccessed 25 Sep 2026
- OuterBox: LLMO and GEO, what we knowaccessed 25 Sep 2026
- Wikipedia: Generative engine optimizationaccessed 25 Sep 2026


