GEO, AEO, GSO: what actually separates them, and which one applies to you

GEO (Generative Engine Optimization), AEO (Answer Engine Optimization) and GSO (Generative Search Optimization) all name the same concern: getting a business cited when an AI writes the answer instead of returning a list of links. GEO is the most established term, coined in a Princeton research paper published on November 16, 2023. AEO is the oldest, inherited from voice assistants and Google's featured snippets. GSO is a variant used by some agencies and is interchangeable with GEO. For a small business, the acronym does not matter. The only useful question is whether your customers ask an AI, and whether your site gives that AI anything worth citing.

Where do GEO, AEO and GSO come from?

The term GEO (Generative Engine Optimization) was proposed by six researchers from Princeton University and the Allen Institute for AI in a paper posted on arXiv on November 16, 2023 and later presented at the KDD 2024 conference. The authors, Pranjal Aggarwal and colleagues, define a "generative engine" as a system that gathers several sources and writes a response, rather than displaying a list of pages. Their experiment compares ways of rewriting content and measures how often that content surfaces in generated answers. The most quoted figure from the paper is a visibility gain of up to 40% in generative engine responses, with a caveat the authors themselves stress: effectiveness varies a great deal from one domain to another.

AEO (Answer Engine Optimization) predates the generative wave. The term describes optimizing content so it is lifted verbatim as the answer to a specific question: a featured snippet on Google, a reply read aloud by Siri or Alexa. Jason Barnard, writing for Search Engine Land on April 29, 2025, proposes a three-layer reading: the search engine that ranks pages, the answer engine that answers a question, and the assistive engine that recommends a solution. In that reading, AEO targets the second layer, and what the industry now calls GEO targets the third.

GSO (Generative Search Optimization) is the least established of the three. It appears mostly on agency websites, often British or European, which use it as a synonym for GEO with an emphasis on Google's AI Overviews. Wikipedia's article on Generative Engine Optimization lists AEO, AIO (Artificial Intelligence Optimization), LLMO (Large Language Model Optimization) and "AI SEO" as variants, but not GSO. The same article notes that no consensus definition distinguished these terms in the academic literature as of early 2026, and that practitioners use them interchangeably. If a vendor sells you GSO rather than GEO, they are selling you the same thing under a different name.

What actually separates GEO, AEO and GSO?

The real difference between GEO, AEO and GSO lies in the type of answer targeted, not in the techniques used. AEO aims to be THE answer to a closed question: "what are your opening hours", "how much does a service cost", "what is the warranty". The content must be short, precise and quotable as is. GEO aims to be one of the sources an AI assembles to answer an open question: "which roofer should I hire in Leeds", "which point-of-sale software for a restaurant". The AI reads several sites, cites a few and ignores the rest. GSO covers the same goal as GEO, with a focus on answers generated directly inside Google.

In practice, all three rest on the same conditions. An engine that writes an answer must first be able to read the page, with content present in the HTML and AI crawlers not blocked. The engine must then be able to extract a passage that keeps its meaning out of context: a sentence that answers a question, structured data that identifies the business, an entity named clearly. The engine must finally have reasons to trust the source: consistent information, mentions elsewhere on the web, no contradictions. Whether you call it GEO, AEO or GSO, the work consists of making a site readable, extractable and credible for a machine that does not click.

Does GEO replace SEO?

No, GEO does not replace SEO (Search Engine Optimization); it sits on top of it. Google Search Central's documentation on AI features, updated December 10, 2025, is explicit: there are no additional requirements or special optimizations to appear in AI Overviews or AI Mode, and a page must be indexed and eligible to be shown with a snippet in Google Search to be cited there as a link. In other words, on Google, a site invisible in SEO is invisible in GEO. A good ranking does not guarantee a citation, though: the article "What an AI visibility scan actually measures, and what it cannot" on this blog details which signals sit on top of classic SEO.

What changes is the traffic a presence in the results brings back. Ahrefs measured on February 4, 2026, across 300,000 keywords compared between December 2023 and December 2025, that the click-through rate of the first position falls by 58% when an AI Overview is displayed. Ranking first without being cited in the overview means keeping your spot and losing more than half of your clicks. Search and generative answers coexist for the same users; the difference is who gets the click when the answer is already on the page.

Which one applies to you, depending on your business?

The practice that applies to you depends on the question your customers ask, not on the acronym of the moment. Three situations cover most small and mid-sized businesses.

• Local shop or local service: your customers ask closed questions, opening hours, prices, booking, service area. AEO logic dominates: short, accurate answers, identical everywhere, with structured data that identifies the business. GEO starts to matter as soon as the question becomes "which tradesperson should I pick", because the AI then compares several sources.
• B2B company or specialist provider: your customers ask open questions, compare offers, look for a recommendation. GEO logic dominates: pages that explain what, for whom and at what price, with self-contained passages an AI can lift without distorting them. AEO remains useful for the definition-type questions prospects type before choosing.
• Online store: both stack up. Product pages fall under AEO, precision, availability, price, while buying guides fall under GEO. Watch the platform: Shopify, Wix, Webflow and Framer lock certain files at the site root, and some signals simply cannot be set.

In all three cases, GSO adds nothing to GEO. The term can serve as a marker if your market is mostly exposed to Google's AI Overviews. But the same signals serve Google, ChatGPT, Perplexity, Gemini and Le Chat. Optimizing for a single AI means betting on the market share of a single company.

When is none of the three your priority?

None of the three practices is your priority if your site has nothing to cite. An AI lifts facts, explanations, comparisons, answers to questions. A five-page brochure site with a tagline, a team photo and a contact form offers no usable passage, and no optimization will change that. The budget is better spent on a services page that explains what you do, for whom, and at what price. The article "How much does an AI visibility audit cost in 2026?" on this blog gives the price ranges to weigh that against.

The same reasoning applies if your reputation does not exist outside your own site. Generative engines cross-check sources: a name that appears nowhere else, not in a trade directory, not in a review, not in a local news article, stands little chance of being recommended even with a perfectly structured site. In that case, external mentions come before optimization. Finally, if your customers arrive by direct referral or through a physical network, and none of them ever asks an AI anything, the question does not arise yet. It may arise in two years, and it is better to know that than to assume it.

How do you know whether your customers ask an AI?

The first clue is your own traffic: the article "What AI Overviews did to traffic in France, in nine days" on this blog details what Google's AI answers changed for sites within days of a rollout. The second clue is demographic: if your customer base is young, the question is no longer whether they use ChatGPT but how often. The third clue is the simplest: ask ChatGPT, Perplexity or Gemini the question your customers ask you, and look at who gets cited.

To move past impressions and measure, an AI visibility scan checks what your site does or does not allow a generative engine to do. Biencité's method, described at /en/methode, examines 19 signals across 3 axes: can AI crawlers read the site, is the content structured to be lifted into an answer, can an AI agent understand the services on offer. The scan is free, read-only and requires no account: it reads the homepage and the public files, installs nothing and changes nothing. It does not promise a citation; it measures eligibility. A signal that cannot be verified leaves the calculation instead of counting as zero, and the report says how many signals were actually checked.

What does deciding later cost?

Deciding later costs the place a competitor takes in the answers in the meantime. An AI that cites three sources for a given question will not add a fourth out of fairness: it picks the ones that give it the most reliable material. Every week your site has nothing extractable, the same three sites settle into the answer, and a citation habit is harder to dislodge than a ranking. The name of the discipline has no bearing on that mechanism. What does is knowing today whether your site is readable and what it has to offer an answer.