AEO vs GEO: Same Job, Two Names, and What Really Differs

Key points

• GEO comes from a research paper first posted in November 2023. Neither term has an agreed industry standard.
• In Vector Index AI's August and September 2026 samples, ChatGPT, Gemini and Perplexity leaned on different sites for local buying questions, so the engine list in a proposal tells you more than its acronym.
• Before you hire for either, ask which engines, which questions, how many runs, and how a citation is counted.

What is the difference between AEO and GEO?

	AEO	GEO
Full name	Answer engine optimization	Generative engine optimization
Where the name comes from	Names the work after the answer engines	A research paper, "GEO: Generative Engine Optimization," first posted in November 2023 and accepted to KDD 2024
Agreed standard	None	None
What you're trying to win	Your business named, described correctly and cited in an AI answer	The same
Engines in scope	ChatGPT, Perplexity, Gemini, Claude, Google AI Overviews, AI Mode	The same
What actually changes the work	The engines and the buyer questions checked	The same

The only row that differs is where the name came from. HubSpot, which uses AEO as its umbrella term for ChatGPT, Gemini, Perplexity and Google AI Overviews, puts it plainly in its AEO vs GEO explainer: "There's no industry standard on this, because the discipline itself is still relatively new." So when a vendor tells you GEO is the newer, better thing, or that AEO is the real discipline, they're describing their own vocabulary.

Where did the term GEO come from?

GEO has a paper you can read. The GEO paper on arXiv describes generative engines as systems that "typically satisfy queries by synthesizing information from multiple sources and summarizing them using LLMs." Its abstract says GEO "can boost visibility by up to 40% in generative engine responses."

That 40% figure shows up in a lot of GEO sales pitches, so it helps to know what it measured. Vector Index AI went through the per-query results the authors released:

• Left unchanged, the chosen source averaged 19.4% across 989 queries on the paper's visibility score (it counts the words in answer sentences that cite the source, weights sentences near the start more, and divides by the total for all five sources).
• Rewritten with the method labelled Quotation Addition, the same source averaged 27.3%. That's 7.9 percentage points, a 40.6% relative change.
• Query by query, the rewrite scored below the unchanged source on 27.6% of the 989.
• No field in the results file names an engine or a model, so it can't tell you how ChatGPT or Gemini would treat your pages.
• The released prompt for that method says to add quotes "even though fake and artificial."

So "up to 40%" is a relative gain on a research benchmark, from about a fifth to just over a quarter on that score, and the same rewrite did worse on more than a quarter of the queries. If a GEO pitch leans on it, ask whether any tactic in the plan adds quotes, statistics or sources that aren't real.

Do you need both AEO and GEO?

No. You need one piece of work, under whichever name your team already uses. Google's guidance on AI features for site owners says "There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary," and that you can apply the same foundational SEO best practices to its AI features as to Google Search overall.

The same page adds that "AI Mode and AI Overviews may use different models and techniques, so the set of responses and links they show will vary." If two features from one company can show different links, separate engines can too, which is why the engine list in a proposal matters more than its title.

If one vendor quotes you an AEO program and another a GEO program, lay the deliverables side by side and ignore the headings. Where the engines, questions and reporting match, you're comparing the same service.

What changes the work in AEO vs GEO, if not the label?

The engines you check change it. Vector Index AI's study of which sites AI engines cite for local buying questions looked at 168 answers to 38 question wordings that name Cincinnati or say "near," sampled on 24 and 25 August and 16 September 2026 through each engine's API with web search on.

Engine (API, Aug and Sep 2026)	Answers	What it cited
ChatGPT	68	bbb.org in 14
Gemini	68	bbb.org in none, reddit.com in 14
Perplexity	32	reddit.com in 13
All three	168	yelp.com in 1

Read those as what happened on the days sampled, not as rates. It's one city, most wordings were asked once per engine, API answers aren't consumer-app answers, and Claude and Google AI Overviews weren't sampled. Still, a site that showed up in 14 of ChatGPT's answers showed up in none of Gemini's. A plan that checks only one engine can't show you a split like that, whatever it's called.

How do you check what an AEO or GEO proposal will actually do?

Ask these six questions of any proposal, and get the answers in writing:

1. Which engines, by name? ChatGPT, Perplexity, Gemini, Claude, Google AI Overviews and AI Mode can each answer differently, so one engine's results don't speak for the others.
2. Which questions? You want the questions your buyers type, in their wording, including ones that don't name your business.
3. How many times is each question asked, and on which dates? One screenshot is one reading. Repeat runs on recorded dates let you tell a pattern from a one-off.
4. What counts as a citation? A linked source, a mention without a link, or both. Vector Index AI's local study, for example, didn't count a domain mentioned in the text without a link.
5. Does any tactic add quotes, statistics or sources that aren't real? The GEO paper's released prompts allowed it. You shouldn't.
6. What do you get to keep? Each recorded answer with its sources, engine, model and date, so you can recheck the same questions yourself later.

Hypothetical example: Proposal A is called an "AEO program" and checks 10 questions, once each, on ChatGPT. Proposal B is called a "GEO program" and checks 25 questions, 4 times each, on 5 engines. A gives you 10 recorded answers from one engine. B gives you 500 across five, so you can compare engines side by side. The acronyms tell you nothing about that gap. The six answers above do.

How do you settle AEO vs GEO for your business?

Settle it by looking at what the engines say about you. Start with what generative engine optimization covers and how Vector Index AI audits it. The audit puts 25 buyer questions, each asked four times, to ChatGPT, Gemini, Claude, Perplexity and Google AI Overviews under recorded conditions. You get a written report showing where your business appears, how it's described, and which changes deserve your attention, so your next decision rests on what the engines actually said.