AI visibility, AEO and GEO, defined in plain words.
AI visibility is how often AI assistants such as ChatGPT, Perplexity, Claude and Google AI Overviews name your brand when people ask about your category. AEO and GEO are two names for the work of raising it. Every term below opens with a one-sentence definition, then the detail and a source.
What is AI visibility, and what are AEO and GEO?
- AI visibilityAlso: AI search visibility
AI visibility is how often AI assistants such as ChatGPT, Perplexity, Claude and Google AI Overviews name your brand when people ask about your category.
It is measured per question and per engine, usually as a mention rate. Unlike a search ranking there is no fixed position: the same question can name you in one answer and leave you out of the next, which is why it has to be sampled, not checked once.
- AEOAnswer engine optimization
AEO is the work of getting your brand named, and your pages cited, in the answers AI assistants give.
In practice it means publishing pages that answer buyer questions directly, earning places on the third-party pages engines cite, and making sure AI crawlers can read your site. An AEO tool measures whether that work is moving the answers.
- GEOGenerative engine optimization
GEO is another name for the same work as AEO: improving how generative AI engines describe and recommend you.
The term comes from a 2023 research paper, GEO: Generative Engine Optimization (Aggarwal et al.). AEO and GEO are used interchangeably; neither is a separate discipline from the other. See what a GEO tool does.
How is AI visibility measured?
- Mention rate
Mention rate is the share of AI answers to a question that name your brand.
Named in 6 of 20 answers is a 30% mention rate. On its own that figure hides how uncertain it is, which is what a Wilson interval is for.
- Wilson intervalWilson score interval
A Wilson interval is the range a measured percentage could plausibly sit in, given how many answers it is based on.
Named in 6 of 20 answers is 30%, with a 95% Wilson interval of about 14.5% to 51.9%. Named in 60 of 200 is also 30%, but the interval narrows to about 24.1% to 36.7%. Same number, very different certainty.
It was introduced by E. B. Wilson in 1927 and is the standard interval for a proportion from a small sample (reference). Proofsource puts one on every percentage; see the methodology.
- PromptAlso: tracked question
In AI visibility, a prompt is a question tracked across AI engines, written the way a buyer would ask it.
"What's the best AI visibility tool for a small team?" is a prompt. Tools price by how many prompts you track, because each one is asked on every engine, every time the tool samples.
- Buyer questionAlso: unbranded question
A buyer question is a question about your category that does not name your brand, written the way someone choosing a product would ask it.
"Which electric SUV is best for a family of five?" is a buyer question. These are the real test of AI visibility, because the engine has to choose to name you. In the public Tesla example (Oct 4, 2026), 53 of 100 answers to 25 buyer questions named Tesla.
- Prompt coverageAlso: question coverage
Prompt coverage is how much of your set of tracked buyer questions AI engines answer with your brand named, broken down by question, topic and engine.
An average mention rate can hide a topic where no engine names you. In the Tesla example, Google AI Overviews named Tesla in 4 of 5 solar panel installation answers and Claude in none of the same 5.
- Recommendation
In an AI answer, a recommendation is a mention that endorses your brand, usually by putting it on the answer's shortlist or naming it as the pick for the buyer's situation.
Every recommendation is a mention, but not every mention is a recommendation: a brand named last, or named as the option to avoid, is mentioned without being recommended. Telling them apart takes reading the answer, which is why position and tone are read beside the mention rate.
- Named insteadAlso: competitors in the answer
The brands named instead are the other brands that appear in AI answers to your buyer questions, ranked by how often each is named.
They are your competitors as the engines see them, which is not always the list you would write. In the Tesla example, the competitors named most often across the same 25 buyer questions were Rivian and SunPower, in 13 answers each, then Ford in 10.
What do AI engines read and cite?
- Citation
A citation is a web page an AI engine links to or lists as a source for its answer.
Being named and being cited are different things. An engine can name your brand while citing a competitor's comparison page, or cite your page without naming you. In the public Tesla example (Oct 4, 2026), 100 answers to buyer questions cited 455 different websites, and fewer than 2 in every 100 citations went to tesla.com.
- Query fan-out
Query fan-out is when an AI engine splits one question into several related searches and builds its answer from all the results.
Google says both AI Overviews and AI Mode may issue multiple related searches across subtopics and data sources to build a response (Google Search Central). It is why a page can be cited for a question it never mentions: it answered one of the sub-searches.
- Google AI Overviews
Google AI Overviews are the AI-written summaries Google shows above some search results, with links to the pages they draw on.
Google says a page must be indexed and eligible to show with a snippet to appear in them (Google Search Central). They are one of the four engines Proofsource tracks.
- Source reach
Source reach is the share of AI answers that cite a given website at least once.
It is the companion to citation share. A site cited ten times in one long answer and a site cited once in each of ten answers have the same citation count, but very different reach.
Does AI describe your brand correctly?
- Brand questionAlso: branded question
A brand question is a question that names your brand, such as "What is Tesla?" or "Is Tesla worth it?", used to check how AI describes you rather than whether it names you.
A brand question will mention you almost every time: in the Tesla example, 19 of 20 answers to brand questions named Tesla. That is why brand questions are tracked separately from buyer questions and read for accuracy, not counted as visibility.
- Entity confusionAlso: brand identity confusion
Entity confusion is when an AI answer about your brand describes, or opens with, a different company or thing that shares or resembles your name.
Even a famous name is not immune: in the Tesla example, Google AI Overviews answered "What is Tesla?" by opening with the magnetic unit of the same name. A newer brand whose name is close to a better-known one can be described as someone else entirely. One plain sentence on your site saying what you are, and what you are not, gives engines something to quote.
Can AI crawlers reach and read your site?
- Crawler access
Crawler access is whether the bots AI companies send can fetch and read your pages.
OpenAI, for example, runs separate bots for search (OAI-SearchBot), for training (GPTBot) and for fetching a page a user asked about (ChatGPT-User) (OpenAI docs). A bot can be blocked in robots.txt or, less visibly, at your CDN's edge by a bot-blocking setting. And a bot that gets through can still see an empty page if your text only appears after JavaScript runs.
- llms.txt
llms.txt is a proposed plain-text file at the root of a website that lists its most useful pages for language models.
It was proposed at llmstxt.org. It is cheap to add and harmless, but it is not a ranking lever: none of the four engines we track has said it uses llms.txt to decide what to name or cite, and Google states that you do not need new machine-readable files, AI text files or markup to appear in AI Overviews or AI Mode (Google Search Central).
Treat it as documentation for agents, not as optimization.
What people ask about AI visibility terms
Is AEO the same as GEO?
Yes, in practice. AEO (answer engine optimization) and GEO (generative engine optimization) both mean getting your brand named and your pages cited in AI answers. GEO comes from a 2023 research paper; AEO is more common in marketing.
What is a good AI mention rate?
There is no universal benchmark, because it depends on how crowded your category is. Compare your rate with the brands named most often for the same questions on the same engines, and read the interval: a rate from 20 answers can sit a long way from the true figure.
What is the difference between a mention and a citation?
A mention is your brand's name in the answer text. A citation is a web page the engine links to as a source. You can be mentioned without being cited, or cited without being mentioned, so track both.
Does llms.txt improve AI visibility?
There is no evidence that it does. Google says no special AI text files are needed to appear in AI Overviews or AI Mode, and none of the four engines Proofsource tracks has said it uses llms.txt for ranking. Readable pages and open crawler access matter far more.
See your own mention rate, with its interval.
See which buyer questions name your brand, who gets named instead, and what to fix. 200 answers. 25 Prompts/Question. Top AI engines. 2 days. Free. No card.
Google AI OverviewsGoogle AI Mode
