SEO vs GEO vs AEO: what is the difference, and do you need all three?

Short answer: treat SEO, AEO and GEO as three names for one job. That job is to be the page a system picks when someone asks a question, and to be easy to quote when it does. The labels help you describe where you want to appear. They are a poor reason to split your team, budget or plan three ways.

The short answer: three labels, one overlapping job

Someone asks a question. A system (a search engine, an answer box, a chatbot) goes looking for pages that answer it well. Your job is to be one of those pages, and to be crawlable, indexable and clear enough to be used.

SEO, AEO and GEO each describe a slightly different corner of that job. They are informal labels, and most of the work underneath them is the same. That is our view, and the rest of this page shows where each part of it comes from.

What each term means and where it came from

SEO (search engine optimisation) is the established one: making pages easy for search engines to crawl, index and rank, so people find them in results.

AEO (answer engine optimisation) points at a narrower prize: being the answer itself. Think featured snippets, answer boxes and voice responses, where the system gives one reply instead of a list of links.

GEO (generative engine optimisation) points at AI-written answers, where a model composes a response and may cite or mention sources as it goes. It is the only one of the three with a named research paper behind it: Aggarwal et al., “GEO: Generative Engine Optimization”, accepted to KDD 2024. More on what that paper does and does not show below.

We found that the top-ranking pages for these terms use AEO and GEO inconsistently. That is our own observation, and we know of no official definition for either. Some treat AEO as a subset of GEO, some treat them as the same thing, and some tie them to different surfaces. For the longer treatment of the GEO side, see what GEO is and GEO vs SEO.

SEO vs AEO vs GEO at a glance

	SEO	AEO	GEO
Surface	Search results pages	Answer boxes, featured snippets, voice answers	AI-written answers that cite or mention sources
Goal	Rank and earn the click	Be the single answer shown	Be cited or described accurately in the response
What you can measure	Indexing, impressions, clicks, positions	Whether you hold the answer for chosen queries	Whether and how you are cited for a fixed set of prompts

Read the table as a map of emphasis. One page can serve all three columns at once, and good pages usually do.

Where they overlap

They overlap on most of the work.

Google’s guidance on its AI features (AI Overviews and AI Mode) is direct about this. To be eligible as a supporting link, a page must be indexed and eligible to be shown in Google Search with a snippet, and Google says there are no additional technical requirements. It also says specific optimisation is not required for these features, and that existing SEO fundamentals stay worthwhile: allowing crawling in robots.txt (and at your CDN or host), internal links, good page experience, important content available as text, and structured data that matches the visible page.

So a crawlable, indexable, clearly written page with accurate information sits underneath all three labels. If that foundation is broken, no label fixes it. If it is sound, you have done most of the work for each.

Where they genuinely differ

They do differ, though by less than the sales pages suggest.

• The surface. A ranked list of links, a single boxed answer and a written AI response are different places to appear, and you are represented differently in each.
• The unit of success. In classic SEO you usually want the click. In AEO you may be the answer even if nobody clicks. In GEO you want to be cited or described correctly, which may or may not send anyone to your site.
• Measurement. Rankings and clicks have mature tools. Citations in AI answers are harder to track, because answers vary between runs and across products.
• Crawler access. AI companies run their own crawlers with separate purposes, so robots.txt choices matter in new ways (see below).

What the platforms say, what research shows, and what is just practice

Mixing these three kinds of claim is how a lot of confident nonsense gets published, so here they are kept apart.

What the platforms document

Google. For AI Overviews and AI Mode: indexed plus snippet-eligible, no extra technical requirements, SEO fundamentals still apply. Google says these features surface links to supporting websites, and that AI Overviews only appear when its systems judge them additive, so they often do not trigger. Google treats robots.txt rules for Googlebot as the control over crawling for Search, including its AI features. To limit what is shown from your pages, it points to nosnippet, data-nosnippet, max-snippet and noindex. Google-Extended is a separate control for AI training and grounding in some of Google’s other systems.

OpenAI. OpenAI documents separate user agents. OAI-SearchBot is for surfacing sites in ChatGPT’s search features, and sites that block it will not be shown in ChatGPT search answers (though they can still appear as navigational links). GPTBot crawls content that may be used to train its foundation models. ChatGPT-User visits pages for certain user actions, and OpenAI notes that robots.txt rules may not apply to it because a user starts those visits. You can allow one and block another.

robots.txt itself. RFC 9309 defines the rules crawlers are “requested to honor” and states plainly that they “are not a form of access authorization”. It is a request that well-behaved crawlers follow. It does not lock anything. For the practical setup, see crawler access. Other AI companies publish their own crawler names, so check each operator’s documentation before writing rules for it.

What research shows

The Aggarwal et al. paper set out GEO as a research problem. The authors built GEO-bench, a benchmark of 10,000 queries across domains, and tested ways of rewriting source pages to raise their visibility in generated answers. They report that adding citations, quotations from relevant sources and statistics helped visibility in their tests, and that what worked varied by domain. Know the conditions before you lean on it: most results come from the authors’ own two-step generative engine setup, with visibility scored by metrics they defined (partly judged by GPT-3.5), plus a smaller test on Perplexity. It is a useful signal about what generative systems may favour. It is not a rulebook for today’s ChatGPT, Gemini or AI Overviews, and it promises no result for your site.

What is just practice

The following is our recommendation. No platform documents it as a requirement: keep technical SEO healthy, put a clear direct answer near the top of each important page, keep facts accurate and sourced, decide deliberately which crawlers you allow, and describe your business the same way everywhere it appears. It is cheap, sensible, and comes with no guarantee. Our principles and how AI answers happen go into more depth.

Do you need all three? A sensible order of work

You need the work. You do not need three programmes. This is the order we would follow:

1. Fix the foundation. Pages crawlable, indexed and eligible for snippets. This is SEO, and Google’s documentation says it is also what makes a page eligible for its AI features.
2. Write for the answer. Put a clear, direct response near the top of each page that matters. This serves answer boxes, and in our view it makes a page easier for any system to quote.
3. Keep facts accurate and sourced. Dull, and probably the most durable item on this list.
4. Set crawler rules on purpose. Decide which search and AI crawlers you want, using each operator’s documentation, then set robots.txt to match.
5. Make your description consistent. Your name, what you do and who it is for should read the same on your site, your profiles and your listings.

None of these steps needs its own budget line per acronym. They are one body of work under three labels.

How to tell whether any of it is working

Start with what is well established. Google says visits from AI Overviews and AI Mode are counted in Search Console’s Performance report, within the “Web” search type, alongside the rest of your search traffic. Indexing, impressions and clicks there tell you whether the foundation holds.

Answer boxes and AI citations are rougher to measure. Pick a fixed set of questions your customers actually ask, check how you appear for them on a regular schedule, and record what you see, including how you are described. Treat each check as a sample, because answers vary from one run to the next. Our notes on measuring progress cover this in more detail.

Be wary of anyone who promises a result. Nobody can guarantee your site will be cited in an AI answer, and Google’s own documentation describes eligibility, not placement.

Questions

The common questions on SEO, AEO and GEO are answered below.