AI search basics
AEO vs GEO vs SEO: what's the difference, and which do you need?
SEO, AEO, GEO, AIO, LLMO. Five labels for how people find you now. Here's what each one means, where they overlap, and what to do first.
If you've looked into how AI is changing search, you've probably met a wall of acronyms. SEO, AEO, GEO, AIO, LLMO, "AI SEO". People search for "seo vs aeo vs geo vs aio" because the industry hasn't agreed on names yet.
The good news: the ideas underneath are simple. Here's what each term means, how they fit together, and where to start.
SEO: getting your pages ranked
Search engine optimisation is the familiar one. It's the work that helps your web pages rank in Google and Bing results: technical health, relevant content, links from other sites, and a good experience for visitors.
The reward for SEO is a click. Someone searches, sees your page in a list, and visits.
AEO: becoming the answer
Answer engine optimisation grew up around featured snippets and voice assistants, where the search engine reads out one answer instead of showing ten links. AEO is about writing content that answers a question so clearly and directly that a machine can lift it out and use it.
The reward for AEO is being the quoted answer, whether that's a snippet, a voice reply or a line in a Google AI Overview.
GEO: being named inside AI answers
Generative engine optimisation covers assistants that write a fresh answer every time: ChatGPT, Perplexity, Gemini, Claude, Copilot and Google's AI Mode. Ask one "who are the best accountants for small charities in Leeds?" and it writes a short reply that names a few firms and cites a few sources.
GEO is the work that makes your brand one of those names. It goes beyond your own pages to how the wider web talks about you, because AI models build their picture of a business from many sources at once.
The reward for GEO is a mention or citation at the moment someone is deciding.
AIO, LLMO, LLM SEO and AI SEO
These are mostly alternative names for GEO:
- AIO: AI optimisation (sometimes also used for Google's AI Overviews).
- LLMO or LLM SEO: optimising for large language models, the technology behind AI assistants.
- AI SEO: the label many agencies use because it's what clients type.
Don't let the naming put you off. If someone offers you "LLMO", ask what they'll actually do and how they'll measure it.
Side by side
| SEO | AEO | GEO | |
|---|---|---|---|
| Where you show up | Search results pages | Snippets, voice answers, AI Overviews | ChatGPT, Perplexity, Gemini, Claude, Copilot, AI Mode |
| What you win | A click | Being the quoted answer | A mention or citation in the answer |
| Main levers | Technical health, content, links | Clear question-and-answer content, structure, schema | Brand and entity clarity, third-party mentions, quotable content |
| How it's measured | Rankings, organic traffic | Snippet and AI Overview appearances | Share of answer, citations, sentiment, AI referrals |
How they fit together
Think of them as layers, not competitors.
- SEO is the foundation. Many AI assistants search the web before answering. If your site is slow, hard to crawl or thin, it's less likely to be read at all.
- AEO makes your content usable. A page that answers "how much does X cost?" in the first two sentences is far easier for any machine to quote than one that buries the answer in paragraph nine.
- GEO makes your brand believable. AI models lean on what other sources say: reviews, directories, press coverage, comparison articles, forums. If the wider web is quiet about you, the model has little reason to recommend you, however good your own site is.
Why a brand can rank on Google and still be missing from ChatGPT
This is one of the most common questions we hear. Ranking well means Google trusts a page. Being recommended by an AI assistant means the model is confident about your brand: what you do, who you're for, and that others vouch for you.
The gap usually comes from one of three things:
- Your business is described differently on your site, LinkedIn, directories and review sites, so the model can't connect them.
- You have very few mentions on the third-party pages that AI assistants already cite in your category.
- Your pages talk about you rather than answering the questions buyers actually ask.
Which do you need?
Most businesses need all three working from one plan, but not all at once. A sensible order:
- Measure first. Ask the questions your buyers ask, across the main AI assistants, and note who gets named and which sources get cited.
- Fix the foundations. Crawlability, page structure, and a consistent description of your business everywhere it appears.
- Answer real questions. Build pages that answer your buyers' questions directly and specifically.
- Earn mentions. Reviews, coverage, comparisons and expert contributions on the sites AI already trusts in your sector.
- Track and repeat. AI answers change often, so check monthly.
That first step is exactly what our free AI search audit does.
Questions people ask
Is GEO the same as AI SEO?
In practice, yes. GEO (generative engine optimisation), AI SEO, AIO (AI optimisation), LLMO (large language model optimisation) and LLM SEO all describe the same goal: being named and cited in answers written by AI assistants. Agencies pick whichever label their clients search for.
Is AEO just featured snippets?
It started there. AEO began as optimising for featured snippets and voice assistants, which read out one answer. It now also covers Google AI Overviews and AI assistants, but its focus is still on the answer itself: clear, quotable content that answers a question directly.
Do I still need SEO if I'm doing GEO?
Yes. AI assistants with web access often search the web before they answer, and they tend to pull from pages that are easy to crawl, well structured and already trusted. Weak SEO usually means weak AI visibility too.
Which one should a small business start with?
Start with the basics that serve all three: a clear description of what you do and who for, used consistently everywhere; pages that answer your customers' real questions; and reviews and mentions on sites people in your sector trust. Then check how AI assistants describe you.
