Definitions
AEO vs GEO vs SEO: what the terms actually mean
In practice, AEO and GEO describe the same work under different labels, and both sit on top of SEO. The useful way to read them is as layers, not rivals: SEO makes your content retrievable, AEO makes it extractable as a clean answer, GEO makes your brand the one an engine names. Google's position is that none of the new terms are necessary. It has a point.
Last updated 31 July 2026
Why this page exists
The category cannot agree on its own vocabulary, and the confusion is expensive.
Here is the clearest illustration. In 2026, Dimension Market Research published two reports. One valued the answer engine optimisation market at $160.9 million for the year. The other valued the generative engine optimisation market at $1,089.3 million for the same year.
$160.9M
AEO market size, 2026
Dimension Market Research
$1,089.3M
GEO market size, 2026, same research house, same year
Dimension Market Research
Same research house. Same twelve months. A 6.8× difference, because the two reports are drawing the category boundary in completely different places.
Meanwhile Valuates put GEO services at $886 million in 2024, and practitioners across the field describe AEO and GEO as the same discipline with different names.
Somebody is going to quote one of those figures at you in a pitch deck. This page is so you can ask which definition they used.
The layered model we use
Rather than treating these as competing disciplines, treat them as a stack. Each layer depends on the one below.
SEO, Search Engine Optimisation
The foundation. Making content discoverable, crawlable and authoritative.
Crawlability and indexation. Site architecture. Structured data. Page performance. Topical authority. Link acquisition. Genuine content quality.
Still load-bearing. Google confirmed in May 2026 that its generative features run on core Search ranking and quality systems, so this work carries directly into AI Overviews and AI Mode. Google's search revenue rose 19% year-on-year in Q1 2026 with query volume at an all-time high. Nothing here has stopped mattering.
AEO, Answer Engine Optimisation
The extraction layer. Structuring content so an engine can lift a clean, correct answer out of it.
Answer-first page structure. Direct definitions in the opening 40–60 words. Clean heading hierarchy. FAQ structure where warranted. Stable, consistent terminology. Factual specificity and inline sourcing.
Why it's a separate layer: placement is measurable and it matters. Zyppy found 44.2% of LLM citations come from the first 30% of a page, and engines apply per-URL retrieval caps. Historically the term covered featured snippets, People Also Ask and voice results; it has expanded to cover AI-generated answers generally.
GEO, Generative Engine Optimisation
The authority layer. Building enough brand presence that a generative engine names you specifically.
Entity establishment and disambiguation. Digital PR into the sources these systems retrieve from. Review platform consistency. Community presence. Category thought leadership. Cross-platform corroboration of your core facts.
Why it's the layer that matters most: Ahrefs, across 75,000 brands, found branded web mentions correlate 0.664 with AI Overview visibility against 0.218 for backlinks, roughly three times as predictive. Seer Interactive's 2026 behavioural work, across 362,388 responses, suggests models select which brands to recommend from trained knowledge and then find citations to support it. If that holds, this layer determines whether the other two get a chance to matter.
The term itself comes from academic work: GEO: Generative Engine Optimization, Aggarwal et al., presented at KDD 2024, with authors from Princeton, IIT Delhi, Georgia Tech and the Allen Institute for AI.
AIO, AI Optimisation, or AI Overview Optimisation
Ambiguous. Ask what someone means. Used variously for optimisation aimed at Google's AI Overviews specifically, and as a general umbrella for all AI-facing optimisation. Not a term we use, because it resolves to two different things.
And the honest umbrella term
"AI visibility" is the cleanest label available. It describes the outcome rather than the technique, doesn't require an acronym key, and nobody has to defend it as a separate discipline.
What Google says, and why it's mostly right
On 15 May 2026, Google published guidance on optimising for its generative AI features. Its position:
- The AI features are rooted in Google's core Search ranking and quality systems.
- SEO best practice remains relevant and foundational.
- The terms AEO and GEO are not necessary.
Danny Sullivan has said good SEO is good GEO, and that SEO for AI is still SEO. John Mueller has been blunter, noting that a hard push on new acronyms correlates with spam and scamming.
Where Google is right: the mechanics genuinely are shared. There is no secret second algorithm. A separate "GEO audit" as a product is largely repackaging.
Where Google's framing is incomplete: Google speaks only for Google. ChatGPT retrieves through Bing, 87% of SearchGPT citations matched Bing's top ten against 56% correlation with Google's, per Seer Interactive. Perplexity runs its own index of 200 billion-plus URLs with heavy community weighting. A study across 55,936 queries and six LLM search engines found roughly 37% of cited domains never appear in traditional search results at all.
Google's guidance is accurate and covers perhaps half the surface area. That's not a criticism, it's a scope limitation, and it's exactly what you'd expect.
The distinctions people draw, and whether they hold
| Claimed distinction | Does it hold? |
|---|---|
| "AEO is snippets and voice; GEO is generative summaries" | Historically yes, decreasingly. AEO's original scope was featured snippets, People Also Ask and voice. Both terms have drifted to cover AI answers generally. |
| "AEO is Google; GEO is ChatGPT and Perplexity" | No. Common in agency marketing, unsupported by usage. Both terms get applied across all platforms. |
| "GEO is the academic term; AEO is the commercial one" | Largely yes. GEO was coined in the Princeton paper. AEO emerged from practitioner and vendor language. |
| "They're the same thing" | In practice, yes. Most agencies treat them as one integrated discipline and the deliverables overlap almost entirely. |
| "SEO is dead, AEO replaces it" | No. Google query volume is at an all-time high and its search revenue grew 19% year-on-year in Q1 2026. What is genuinely ending is the SEO business model built on billing for rankings and clicks, under a third of Google searches now send a click, per SparkToro's June 2026 research. The practice is healthy; the retainer needs rewriting. |
How to read anyone else's use of these terms
Four questions that will tell you whether you're talking to a practitioner or a pitch.
- "Which platforms does your definition cover?" If the answer is only Google, they're describing SEO. If it's only ChatGPT, they're describing a fraction of the surface.
- "Which definition is that market-size figure using?" The same research house published $160.9M and $1,089.3M for the same year under different labels. If they can't answer, the number is decoration.
- "What's in your AEO deliverables that isn't in your SEO deliverables?" A good answer describes measurement across multiple engines, brand and entity work, and answer-structure changes. A bad answer describes llms.txt.
- "What's your position on Google's May 2026 guidance?" Not having heard of it means they aren't following the field.
Our working definitions, for the record
Answer Engine Optimisation (AEO): Structuring content so that AI systems and search features can extract an accurate, self-contained answer from it.
Generative Engine Optimisation (GEO): Building the brand presence, entity clarity and third-party corroboration that lead generative AI systems to name a specific business in their answers.
Search Engine Optimisation (SEO): Making content discoverable, crawlable, structured and authoritative for search systems, the foundation both of the above depend on.
AI visibility: The measurable outcome of all three. How often, and how prominently, AI systems mention or cite you.
We use these consistently across this site. Others don't. When we quote a figure, we say which definition it came from.
FAQ
Is there any real difference between AEO and GEO?
Functionally, very little, most practitioners treat them as one discipline and the deliverables overlap almost entirely. The distinction worth keeping is that AEO describes making content extractable, while GEO describes making a brand nameable. That maps onto genuinely different work, whichever labels you prefer.
Which term should I use?
"AI visibility" if you want to be understood. AEO if you want to be found, it carries more search volume. Either way, define your terms once and stay consistent.
Did Google ban the terms AEO and GEO?
No. Google said they aren't necessary and that its AI features run on core Search systems. That's guidance about mechanics, not a prohibition on vocabulary.
Is SEO dead?
No. Google's query volume is at a record high and its search revenue grew 19% year-on-year in Q1 2026. The SEO business model built on rankings and click volume is in real trouble, because fewer than a third of Google searches now send a click. That's a commercial problem, not a technical one.
Why do market-size estimates vary so much?
Because the category has no agreed boundary. In 2026 the same research house valued AEO at $160.9M and GEO at $1,089.3M, a 6.8× gap driven entirely by definitional scope. Always ask which definition a figure uses.