AEO, SEO, and GEO explained — how answer, search, and generative engine optimization differ, and which your brand needs to stay visible.
Quick answer: SEO optimises pages to rank in search results and earn clicks. AEO shapes content so it is lifted as the direct answer in Google's AI Overviews, featured snippets and voice assistants. GEO makes content and brand signals easy for ChatGPT, Gemini and Perplexity to cite or recommend. All three share one technical foundation but use different scorecards.
Three acronyms now compete for the same line in the marketing budget, and most explanations blur them together. That is a problem, because SEO, AEO and GEO reward different things and are measured in different ways. This guide gives precise definitions, compares them side by side and shows where they overlap, using Google's own documentation, the research paper that named GEO and current usage data.
SEO wins a position in a ranked list of links, AEO wins the answer box above or instead of that list, and GEO wins a mention inside an answer that a generative AI system writes. The content can be the same; the unit of success is different.
AEO and GEO are often used interchangeably. The useful distinction is the surface: AEO targets answers inside a search engine's results, while GEO targets standalone AI assistants whose answer may be the whole experience.
Because a large share of questions are now answered without a list of links. The numbers below are the most reliable recent figures we could trace to their original source.
| Measure | Figure | Source and date |
|---|---|---|
| ChatGPT weekly active users | 900 million, up from 800 million in October 2025 | TechCrunch, February 2026 |
| Gemini app monthly active users | 950 million | Alphabet Q2 2026 earnings call, July 2026 |
| US Google queries showing an AI Overview | 6.49% (January 2025), 24.61% (July 2025), 15.69% (November 2025) | Semrush, 10M+ keywords |
| Google searches that produced an AI summary | About 18% | Pew Research Center, browsing data from 900 US adults, March 2025 |
| US adults who have used ChatGPT | 34% overall, 58% of under-30s | Pew Research Center, survey February to March 2025 |
| Share of ChatGPT conversations about practical guidance, seeking information or writing | Nearly 80% | NBER Working Paper 34255, 2025 |
Note the spread on AI Overviews: Semrush's keyword panel and Pew's real-user browsing data measure different things, so the honest answer is "somewhere between roughly one in six and one in four US searches, depending on month and method", not a single figure.
One of our own tools taught us to check what a visitor, or a crawler, actually receives. A client reported a report filter as broken three times. We fixed four genuine interface bugs, and none of them was the cause: a missing Cache-Control header meant the browser and host kept serving an old page. Search engines and AI crawlers can be served a stale or blocked page in exactly the same way.
Clicks are changing too. Pew found that users who saw an AI summary clicked a traditional result in 8% of visits, against 15% for users who did not. Google, for its part, told investors in July 2026 that it is "sending billions of clicks to websites every week through AI features in Search". Both can be true at once. We cover the click data and brand measurement in depth in our guide to the zero-click internet.
SEO optimises for ranking signals, AEO for extractable answers and GEO for citation signals. They share a foundation, but the emphasis shifts.
Google's own explanation of how ranking works names five groups of factors: the meaning of the query, the relevance of the content, its quality, its usability and the searcher's context. Quality includes whether "prominent websites link or refer to the content", and usability includes "mobile-friendly content that loads quickly". Google's guidance on helpful content adds that its systems look for experience, expertise, authoritativeness and trustworthiness, and that "trust is most important".
Google is unusually direct here. Its documentation on AI features says "there are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary", and that "there's also no special schema.org structured data that you need to add". It also explains that both features may use "query fan-out", running several related searches across subtopics before writing an answer.
Fan-out explains a striking shift. In March 2026 Ahrefs found that only 38% of pages cited in AI Overviews also ranked in the top 10 for the same query, down from about 76% in its July 2025 study. Ranking still helps, but the citation pool is now much wider than page one. AEO in practice means answer-first passages under question-shaped headings, clean tables and self-contained facts. FAQ schema is not a shortcut: since August 2023 Google shows FAQ rich results only for "well-known, authoritative government and health websites". For tactics, see how to make your website visible in Google AI Overviews.
The GEO paper tested nine ways of rewriting a source page across a benchmark of 10,000 queries. The best performers, Cite Sources, Quotation Addition and Statistics Addition, achieved a relative improvement of 30-40% on the paper's main visibility metric, and the authors report that GEO "can boost visibility by up to 40%". Keyword stuffing, the classic SEO habit, offered "little to no improvement".
Off-page signals matter as much. An Ahrefs study of 75,000 brands found that branded web mentions correlated with AI Overview visibility at 0.664, against 0.218 for backlinks. A 2025 study by Chen and colleagues found AI search shows "a systematic and overwhelming bias towards Earned media" over brand-owned content. Our GEO strategy guide turns that research into a plan.
The table below is the short version of this article: same foundations, different goals, different signals and different scorecards.
| Dimension | SEO | AEO | GEO |
|---|---|---|---|
| Goal | A high position and a click | Being the extracted answer, with a source link | Being cited, quoted or recommended in a generated answer |
| Main surfaces | Google and Bing organic results | Google AI Overviews and AI Mode, featured snippets, voice assistants | ChatGPT, Gemini app, Perplexity, Microsoft Copilot |
| Unit of success | Ranking, click, conversion | Inclusion and citation in the answer | Mention, citation, share of answers for a set of prompts |
| Core signals | Relevance, quality, links, usability, context (Google) | Same as SEO; no special markup or files required (Google); coverage of fan-out subtopics | Cited sources, statistics, quotations, fluency (GEO paper); third-party brand mentions (Ahrefs) |
| What does not help | Content made to manipulate rankings | "AI text files" or special schema | Keyword stuffing (10% worse than baseline on Perplexity) |
| Main measurement | Search Console clicks, impressions, position | Search Console "Web" search type (AI features are not reported separately) | Bing AI Performance citations, repeated prompt tests, AI referral traffic |
SEO has mature measurement, AEO is folded into SEO reporting, and GEO is only now getting first-party data.
Search Console's Performance report, rank tracking and organic conversions in analytics remain the core. Nothing about AI search changes that.
Google says traffic from AI features is "included in the overall search traffic in Search Console", reported "within the 'Web' search type". There is no separate AI Overviews filter, so you infer impact from which of your queries trigger AI Overviews and how click-through on those queries moves. Google also says that clicks from results pages with AI Overviews "are higher quality", with users more likely to spend more time on the site, and suggests judging visits by conversions rather than click counts. Our post on measuring AI Overviews traffic covers the method.
The first platform-level data arrived on 10 February 2026, when Microsoft launched AI Performance in Bing Webmaster Tools. It shows citations, cited pages and the "grounding queries" behind them across Microsoft Copilot, Bing's AI summaries and select partners. For other assistants you need a fixed set of buyer prompts, run repeatedly. Answers vary between runs: the GEO researchers sampled five responses per query to reduce statistical deviation, which is a sensible minimum for your own tests too. Add referral traffic from AI assistants as a separate channel in analytics.
They overlap far more than the acronyms suggest. All three need pages that can be crawled, text that exists in the HTML, accurate facts and a brand that other sites talk about.
Google's position is that "the underpinnings of what Google has long advised" carry across to AI search. Independent research partly agrees. The C-SEO Bench study (revised October 2025) found that "most current C-SEO methods are not only largely ineffective but also frequently have a negative impact", and that traditional SEO aimed at improving a source's ranking was substantially more successful.
The GEO paper points the other way on one important detail: content changes helped lower-ranked pages most. Cite Sources raised visibility by 115.1% for the source ranked fifth, while the top-ranked source lost 30.3% on average. So the evidence ranges from "ranking is what matters" to "good content can leapfrog ranking". Our reading is that both hold: ranking gets you into the candidate set, and content quality decides how much of you the answer uses.
The clearest lesson from our own audits in September and October 2026 is that the fixes rarely belong to just one acronym.
The clearest example comes from our own AI website-operations platform, which scans client sites for problems. One client's host served our scanner a bot-challenge page ("One moment, please...", returned as HTTP 200) instead of the real site, so the scanner reported problems such as missing headings that did not exist for human visitors. Search engines and AI assistants face the same risk: if a firewall or bot-protection layer shows them a challenge page, there is nothing to rank, extract or cite. We now check what a crawler actually received before trusting any finding, and the same check belongs in every SEO, AEO and GEO audit.
The second lesson is to verify results the way users and engines see them. On shared hosting the FTP root is not always the site's web root, and an upload to a wrong-but-plausible folder succeeds silently. Re-downloading the file you uploaded proves nothing, so we verify every change over the public HTTPS URL. Whether the change is a title, an FAQ block or a schema fix, it only counts once the live page serves it.
Run one programme with three scorecards, not three separate projects.
Our take: start with SEO foundations, because Google says AI features need nothing extra and C-SEO Bench found ranking-focused work beats most AI-specific tricks. Then format your key pages for extraction: answer first, question-shaped headings, tables and sourced statistics, which serves AEO and is precisely what the GEO paper rewarded. Then put real effort into GEO's distinctive half, earned third-party mentions, because the correlation data and the earned-media research both say that is where AI answers look. Be wary of anyone selling GEO as a separate technical trick. The evidence says it is mostly good SEO, honest content and PR, measured differently. If you want an outside view of where your site stands, our SEO team can audit all three, or you can get in touch.
Broadly, yes. "AI SEO", "LLM SEO" and "LLMO" are informal labels for the same goal: being cited or recommended by AI assistants. GEO is the term with an academic definition, from the 2024 KDD paper by Aggarwal and colleagues, which also introduced visibility metrics for measuring it. Whatever the label, ask what is being optimised and how it is measured, because that tells you whether the work is substance or rebranding.
Partly. Google says its Google-Extended token "does not impact a site's inclusion in Google Search nor is it used as a ranking signal". But Google-Extended also controls grounding in the Gemini app, so blocking it can reduce visibility there. Blocking OpenAI's GPTBot stops training use, while OAI-SearchBot is the crawler that surfaces sites in ChatGPT search. Decide bot by bot rather than with one blanket rule.
It is optional. Google's AI features documentation says you do not need to create AI text files to appear in AI Overviews or AI Mode, and in June 2025 Google's John Mueller wrote that no AI system currently uses llms.txt. It costs little to add, but it should come well after crawl access, server-rendered content and accurate, well-sourced pages in your priorities.
Not on current evidence. Google says the fundamentals of its long-standing advice apply to AI Overviews and AI Mode, and the C-SEO Bench study found traditional SEO aimed at ranking was substantially more effective than most AI-specific methods. What is changing is measurement: rankings alone no longer capture visibility, so citations and AI referrals need tracking alongside clicks.
Start with the platforms with the largest reach: Google, including AI Overviews and AI Mode, ChatGPT and Gemini, then Perplexity and Copilot. ChatGPT reported 900 million weekly users in February 2026 and the Gemini app 950 million monthly users in July 2026. Test your own buyer questions on each, because citation sources differ noticeably between platforms.