SEO vs AEO vs GEO: What's Actually Different

SEO gets your page ranked in a list of links. AEO and GEO get your brand named inside the answer an AI writes. AEO (answer engine optimization) and GEO (generative engine optimization) are the same job with two names. How different that job is from SEO depends on which engine you mean: for Google, it’s mostly SEO. For ChatGPT, much less so.

That’s the whole answer. The rest of this piece is the evidence, because most “SEO vs AEO vs GEO” posts argue from vibes, and the numbers tell a more useful story.

The three terms, defined

	SEO	AEO	GEO
Stands for	Search engine optimization	Answer engine optimization	Generative engine optimization
Goal	Rank a page so people click it	Get the brand named, cited and described correctly in AI answers	Same as AEO
Where it shows up	Google and Bing results pages	ChatGPT, AI Overviews and AI Mode, Perplexity, Claude, Gemini	Same as AEO
Unit of success	A ranking and a click	A mention, a recommendation, a citation	Same as AEO
Where the term comes from	Two decades of search marketing	Marketers and platforms	The 2024 GEO paper

AEO vs GEO: pick one and move on

I use AEO because it’s what more people search for. GEO has the academic pedigree. LLM SEO and AI search optimization mean the same thing too. If a vendor tells you AEO and GEO are different disciplines with different price tags, ask them to show you the different work. They can’t, because there isn’t any.

For Google, AEO is mostly SEO

Google says optimizing for its AI features “is … still SEO”. The data mostly agrees. Ahrefs found 38% of AI Overview citations come from pages in Google’s top 10. That’s down from about 76% a year earlier, as fan-out queries took over, but it’s still a strong link.

What Google adds on top of classic SEO is reputation. Branded web mentions correlate with AI Overview visibility at ρ = 0.664, against 0.218 for backlinks, and YouTube is now the most-cited domain in AI Overviews. For local and ecommerce answers, Google names your Business Profile and Merchant Center feeds explicitly.

So for Google: rank, get mentioned, get on YouTube, keep your feeds right.

For ChatGPT, it’s a different game

This is where “AEO is just SEO” breaks. Only about 8% of the URLs ChatGPT cites rank in Google’s top 10. Off-site mentions barely correlate with ChatGPT visibility (ρ = 0.15, against 0.65 for AI Overviews, per Ahrefs). And ChatGPT has the strongest freshness bias of the engines: the pages it cites are 458 days newer than organic results.

Two more differences matter:

• Most answers don’t search at all. Similarweb found only 6.8% of ChatGPT conversations included web citations in May 2026 (US, desktop). Most of the time the model answers from what it already believes about you, which is built from what other people have written about you.
• The crawler doesn’t run JavaScript. Vercel found ChatGPT’s and Claude’s crawlers don’t execute it. A page Google renders fine can be a loading spinner to ChatGPT.

ChatGPT is also where the AI traffic is: more than 80% of AI referrals to the top 1,000 domains in mid-2025. So the engine where SEO transfers least is the one that matters most.

Side by side: what changes and what doesn’t

	SEO	AEO / GEO
Research input	Keyword tools, search volume	Real prompts from customers (signup forms, sales calls), plus Search Console and forums
Main lever	Your pages and your backlinks	What other people say about you: review sites, Reddit, YouTube, lists, Wikipedia
On-site basics	Crawlable, fast, relevant, well-linked	The same, plus answer-first sections, real numbers, server-rendered HTML
Freshness	Matters for some queries	Matters more, especially for ChatGPT
What you measure	Rankings, clicks, conversions	Visibility % per engine across many runs, recommended vs cited vs accurate, self-reported AI signups
Stability	Rankings move slowly	Less than 1 in 100 chance of the same brand list twice

SEO asks “does my page rank?” AEO asks “what does the internet already say about us, and can the machines hear it?”

What doesn’t carry over

Some SEO habits are being resold as AEO tactics. The evidence says they don’t work:

• Schema for AI citations. Ahrefs tested 1,885 pages that added schema against 4,000 controls. A raw +43% in AI Mode citations became +2.4% against the control group, and not significant. Use schema for rich results, not for AEO.
• llms.txt. 97% of files got zero requests in a month. Google says its Search ignores them.
• Self-promotional “best X” listicles. When a brand’s own listicle was cited, the brand was left out of the recommendation 69% of the time (Lily Ray).
• Branded prompts in your score. 77.6% of answers to brand-name questions cite the brand’s own site. Mixing them into visibility tracking inflates the number without anything real changing.

Measurement is the biggest difference

SEO has twenty years of stable rankings and referral data. AEO has neither. AI answers vary run to run, so rank position is meaningless and a single check proves nothing. Rand Fishkin suggests 60 to 100 runs per prompt and reporting visibility percentage, per engine. ChatGPT’s apps strip referrers, and AI Overview clicks sit inside google/organic, so analytics undercount. PostHog says half the referral bucket leaks.

That’s why the most reliable AEO dataset isn’t a dashboard. It’s a signup form field: “AI assistant”, then “which one, and what did you ask?”

So which should you invest in?

If most of your demand comes through Google, keep doing good SEO and add the reputation work: reviews, YouTube, genuine mentions. If your buyers use ChatGPT, SEO alone won’t get you there, and the work shifts to off-site reputation, answer-first pages, freshness and honest measurement.

Set expectations either way. AI visitors convert at a median of 1.26x organic (1.05x for B2B SaaS), and AI is roughly 0.2–3% of sessions on most sites. Good traffic, not magic traffic.

I’ve written up the full operating manual, from the Week 1 audit to the scorecard I send clients, in AEO Strategy: How I Actually Run It.