SEO vs AEO vs GEO: What's the Difference and What Matters?

Over the past year a new line item has started showing up in agency proposals: “SEO + AEO + GEO package”. Three acronyms, three line items, three prices.

So are these really three different jobs?

Put two sources side by side and you get an interesting contradiction. Google’s own documentation says there are no special optimizations needed to appear in its AI answers. Meanwhile, a peer-reviewed academic study measured that specific content changes can boost visibility in generative engines by up to 40%.

Both are true. This post explains where that contradiction comes from and what it means for you in practice.

The short answer: SEO aims to rank, AEO aims to be the direct answer, and GEO aims to be cited by generative AI systems. They aren’t separate disciplines but three different measures of success built on the same technical foundation. Google explicitly says AI answers need no separate optimization; the difference shows up in how you write your content.

What is SEO?

SEO (Search Engine Optimization) is the work of getting a page to rank high in search engine results. It’s the sum of technical, content and authority signals.

It stands on three legs:

• Technical: the site can be crawled, indexed and loads fast
• Content: the page genuinely answers what the user searched for
• Authority: other sites link to you, people know your brand

The success metric is clear: rankings and the clicks they bring. It’s a mature discipline with almost three decades of practice behind it.

What is AEO?

AEO (Answer Engine Optimization) aims to have your content shown not as one link in a list, but as the answer itself.

One detail people often miss: AEO didn’t arrive with AI. The term dates back to the rise of Google’s featured snippets (the box at the top of the results) and voice assistants, roughly from 2015 onwards. When you ask a voice assistant “what is X”, it reads one answer from one source. Being that source is what AEO is about.

In practice it looks like this:

• Use the question as a heading and answer it directly underneath
• Write definitions in a single paragraph, without warm-up
• Use tables, lists and step-by-step flows
• Add an FAQ section and structured data

The success metric isn’t a ranking but appearing in the answer box. You may not get the click, because the user gets the answer right there.

What is GEO?

GEO (Generative Engine Optimization) aims to have your content cited as a source by AI systems that generate answers, such as ChatGPT, Google’s AI Overviews and Perplexity.

The term isn’t agency jargon. It was introduced in a 2023 research paper by Aggarwal and colleagues, later published at the KDD 2024 conference. In other words, there’s measurement behind it.

The difference from AEO: in AEO the goal is to be shown as the single source. In GEO the system pulls from several sources, writes a new answer, and mentions you inside it. What decides the outcome isn’t your ranking but whether your sentences are worth quoting.

If you’re thinking about the paid side of AI assistants, I covered that separately in how to advertise on ChatGPT.

The difference in one table

	SEO	AEO	GEO
Goal	Rank	Be the answer	Be cited
Surface	Blue-link results	Featured snippets, voice assistants	AI Overviews, ChatGPT, Perplexity
User behaviour	Clicks	Reads, often doesn’t click	Asks, continues the conversation
Content format	Comprehensive page	Short, clear definitions, tables, lists	Sourced, data-rich, quotable passages
Technical base	Indexing, speed	Structured data, clean headings	Indexing and snippet eligibility
Authority signal	Backlinks	Topical depth	Citing sources, brand mentions
Measurement	Rankings, clicks	Impressions, zero-click visibility	Citations, brand mentions
Around since	~late 1990s	~2015	2023
Needs a separate budget?	Yes	No	No

The last row is the whole post in one line. Here’s why.

What does Google say?

In its documentation on AI features, Google is unambiguous: there are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary. Standard SEO best practices still apply.

The eligibility list is short:

1. The page must be indexed
2. It must be eligible to show with a snippet (no nosnippet or similar restrictions)
3. It must meet Google Search’s technical requirements

Google also notes that meeting these criteria doesn’t guarantee being shown. So any proposal selling “a special technical setup for AI” contradicts Google’s own documentation.

There’s no secret switch for AI answers. They draw on the same index and are judged by the same helpful content standards.

So why does the research say 40%?

This is where the contradiction lives, and where it resolves.

The GEO study tested nine content changes and measured their effect on how visible a source was in generated answers. The pattern was clear:

Method	Measured effect
Citing sources	Among the strongest gains (roughly 30-40%)
Adding quotations from credible sources	Among the strongest gains (roughly 30-40%)
Adding statistics	Among the strongest gains (roughly 30-40%)
Authoritative tone, fluency, simplification	Smaller gains
Keyword stuffing	About 10% worse than doing nothing

The last row matters most. The move most people associate with “optimization”, sprinkling keywords through the text, doesn’t help in generative engines. It hurts.

How the contradiction resolves

The two sources are talking about different things:

	What Google describes	What the research measures
Topic	Eligibility	Selection
Question	Can you get into the candidate pool?	Which pages in the pool get cited?
Answer	Normal SEO is enough	How you write makes the difference

Google tells you how to get a ticket. The research measures who gets on stage once everyone has one.

The practical takeaway: GEO isn’t a replacement for SEO. It’s a writing discipline that sits on top of it. Not a separate budget, but the decisions you make while writing the same content.

What changes in practice

Making one page work across all three surfaces comes down to a few concrete habits.

Make every section answer one question. Use the question as the heading and answer it in the first paragraph underneath. Readers benefit, and answer boxes pull from exactly this pattern.

Back claims with numbers. Not “conversions went up” but “conversions rose from 2.1% to 3.4%”. It’s one of the three highest-impact methods in the research.

Cite your sources. Wherever a number or claim comes from, link to it. It’s honest with the reader and the strongest signal for being cited.

Write definitions without a run-up. The answer to “what is X” should be done by the end of the first sentence. Text that warms up for three paragraphs doesn’t get quoted.

Use tables and lists. Explaining a comparison in plain prose tires the reader and makes extraction harder for machines.

Don’t stuff keywords. It’s been measured: it backfires.

Notice that none of this is special work “for AI”. It’s simply a recipe for good writing. That’s the point.

Which should you prioritise?

It depends on where you stand:

Your situation	Start with
New site, or technical problems	SEO. If you’re not indexed, nothing else matters
Your topics are definitional and frequently asked	AEO. Answer boxes dominate these queries
You’re a local business	SEO + AEO. Maps and answer boxes decide visibility
Your product invites comparison	GEO. People ask assistants “which is better”
B2B with a long sales cycle	GEO. Evaluation increasingly happens in conversation
New brand nobody searches for yet	None of the three. Create demand first

The last row is important. Optimising search for a product nobody searches for is like putting up a sign on an empty street. In that case you need to create demand first, usually with paid channels. I compared the two main options in Google Ads vs Meta Ads.

How do you measure it?

This is where the three really diverge, and most brands still only look at the first.

Surface	What to look at	Where
SEO	Rankings, clicks, sessions	Search Console, Google Analytics 4
AEO	Rising impressions with flat or falling clicks	Search Console (if impressions grow without clicks, you’re likely in the answer box)
GEO	Referral traffic from assistants	GA4 source breakdown: chatgpt.com, perplexity.ai, gemini.google.com

For the third row I recommend setting up a separate segment in GA4. This traffic is usually small but high-intent: the user asked an assistant, compared options, and still clicked through to you.

What happens after the click is a separate question. If the page doesn’t convince, being visible on all three surfaces doesn’t mean much. That’s where your website itself does the work, as I explained in why your business needs a website.

5 common mistakes

1. Treating the three as separate budgets. Same technical foundation, same index, same quality standards. You only pay separately for separate work, and there isn’t any here.

2. Buying a “technical setup for AI”. Google states plainly that no special markup is needed. Structured data is useful, but it isn’t an AI-specific trick.

3. Clinging to keywords. The data is clear: in generative engines, stuffing backfires.

4. Panicking when clicks drop. If impressions rise while clicks fall, you may have landed in the answer box. That’s not a loss, it’s a different kind of visibility.

5. Never setting up measurement. If you can’t see assistant traffic separately, you’ll never know whether GEO is working.

Frequently asked questions

Is SEO dead because of AI search?

No. AI answers draw on the same index, so a page that isn’t indexed doesn’t appear anywhere. What’s changed isn’t that SEO stopped working, but that rankings are no longer the only measure of success.

Do I need special technical setup to appear in AI Overviews?

According to Google, no. Its documentation states there are no additional requirements or special optimizations needed for AI Overviews or AI Mode. The page needs to be indexed, eligible for a snippet, and meet Search’s technical requirements.

Was AEO invented because of AI?

No. AEO grew out of featured snippets and voice assistants, from around 2015. It existed before generative AI; AI answers simply made it more important.

Is keyword density still important?

Not in generative engines. In the GEO research, keyword stuffing performed about 10% worse than making no changes at all. In classic search it’s long been outdated; on the AI side it actively hurts.

What should a small business do about all this?

Forget the three acronyms and focus on one question: am I giving the clearest, most honest answer on the internet to the question my customer is asking? If yes, you’ll show up across all three surfaces. If no, no technical setup will save it.

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Where to start

Try one thing this week: open your highest-traffic page and look at the first paragraph. Is the answer to the question the page promises right there, or does it arrive after three paragraphs of warm-up?

If it’s further down, move it up. That single change satisfies readers, answer boxes and AI assistants at the same time.

If you’d like to see where your site stands across these three surfaces, I can look at your content, your sector and your competitors and tell you clearly where to put the weight. You’ll find what I do on the services page, and you can book a free strategy call with no obligation.

Sources: Google’s position comes from its own developer documentation: AI features and your website and creating helpful content. GEO measurements are from Aggarwal et al., GEO: Generative Engine Optimization (KDD 2024).