SEO wins a ranked link, AEO the direct answer, GEO a citation inside ChatGPT or Perplexity. What each needs, what they share and how to measure them.
LLaunchScaler·Published ·8 min read
SEO is the work of earning a ranked link that someone clicks, AEO is the work of becoming the direct answer on the results page (a featured snippet, a People Also Ask answer, an AI Overview), and GEO is the work of being cited inside a generated answer from ChatGPT, Perplexity, Claude or Gemini. All three rest on the same crawlable, fast, trustworthy site, and they differ in three places: extractable passages, AI bot access and third-party corroboration.
The table below puts the three side by side. The sections after it explain each column with what Google, Microsoft and OpenAI actually document, checked in September 2026.
What is the difference between AEO, SEO and GEO?
The difference is where you appear and what counts as winning. SEO wins when a searcher clicks your blue link. AEO wins when the search engine shows your answer before any click. GEO wins when an AI model names or links your page inside the answer it writes. The work overlaps heavily, but the measurement does not.
SEO
AEO
GEO
Goal
A ranked link someone clicks
Your text shown as the answer on the results page
A mention or linked citation inside a generated answer
Where you appear
Google and Bing organic results
Featured snippets, People Also Ask, AI Overviews, AI Mode
ChatGPT search, Perplexity, Claude, Gemini, Microsoft Copilot
Questions, answered
What people ask about this
01
What is the difference between SEO, AEO and GEO?
SEO aims for a ranked link that a searcher clicks. AEO aims for the direct answer shown on the results page, such as a featured snippet, a People Also Ask answer or an AI Overview. GEO aims for a citation inside a generated answer from ChatGPT, Perplexity, Claude or Gemini.
Question-shaped headings with a self-contained answer under each
Access for each AI crawler, server-rendered text, being described on other sites
What is SEO?
SEO is making a page eligible to be crawled, indexed and ranked, then making it the best result for a query so a searcher clicks it. Success is a position in the organic results and the click that follows. The feedback loop is mature: Search Console reports clicks, impressions and average position for every query and page.
The fundamentals have not changed because of AI. Google's guide to generative AI features says its AI features "are rooted in our core Search ranking and quality systems" and that SEO best practices "continue to be relevant." Bing's webmaster guidelines open with the same point: Bing and Copilot "rely on the same core crawling, indexing, and ranking foundation as traditional search."
What is AEO?
AEO, answer engine optimization, is making your page the source of the answer a search engine shows directly, before the reader clicks anything. On Google that means featured snippets, People Also Ask answers, AI Overviews and AI Mode. The page still has to rank; AEO adds a passage that states the answer cleanly.
Google describes featured snippets as "special boxes where the format of a regular search result is reversed, showing the descriptive snippet first," and says they can also appear inside People Also Ask. You cannot opt a page in. Asked how to mark a page as a featured snippet, Google's documentation answers: "You can't."
AI Overviews follow the same eligibility rule as snippets. To be shown as a supporting link, Google says a page "must be indexed and eligible to be shown in Google Search with a snippet." That is why the snippet controls matter here: nosnippet applies to AI Overviews and AI Mode and "will also prevent the content from being used as a direct input" for them.
The practical AEO habit is structural. Put the question in a heading and the complete answer in the first sentences beneath it, so the passage stands on its own when lifted.
What is GEO?
GEO, generative engine optimization, is making your site something AI models can fetch, understand and cite when they compose an answer. The term comes from a 2023 paper by Aggarwal and colleagues, published at KDD 2024, which reported that optimization could "boost visibility by up to 40% in generative engine responses."
Each engine finds sources differently, which is why GEO needs per-engine attention:
ChatGPT search "sometimes partners with other search providers" and rewrites your question into queries it sends them, according to OpenAI. OpenAI also runs its own crawler, OAI-SearchBot, and says sites that block it "will not be shown in ChatGPT search answers."
Perplexity surfaces sites through PerplexityBot, Claude through Claude-SearchBot, and each operator publishes its own user agent and robots.txt behavior.
Gemini, AI Overviews and AI Mode draw on Google's index.
Copilot draws on Bing's index, and Bing's guidelines define GEO directly: it "focuses on content eligibility for grounding and reference in AI responses."
Bing also sets expectations: "GEO does not guarantee grounding or citations in AI experiences." Nobody can promise a citation, and a vendor who does is guessing.
What do SEO, AEO and GEO have in common?
All three need a page that crawlers can fetch, that returns the right status code, that renders its main text in HTML, loads quickly and carries signals people and machines trust. If Google or Bing cannot index a page, it will rarely be cited in an AI answer either, because most engines ground their answers in a search index.
The shared foundation, in the order it usually breaks:
The page is allowed in robots.txt and has no stray noindex in the meta robots tag or the X-Robots-Tag header.
The main content is in the HTML the server returns, not only after JavaScript runs.
It returns 200, with real 404s for missing pages and one-hop redirects.
It loads fast enough that visitors stay.
It has a clear title, a canonical URL, and facts other sites confirm.
Google's guide makes a point worth repeating for anyone buying "AEO" services: for Google Search you can ignore tactics like "chunking" content, creating llms.txt files, or pursuing inauthentic mentions. That statement covers Google. Other engines are separate questions, and you should check what each one documents.
What actually differs between them?
Three things change as you move from SEO toward GEO. Answers need passages that stand alone. Each AI company runs its own crawlers, which your robots.txt and firewall must let in. And AI answers lean on what other sites say about you, not only what your own page says. A site can rank well and still fail on all three.
Extractable passages
A ranked page can make its point over 2,000 words. An answer box or an AI answer lifts a few sentences. Write each section so its first 40 to 60 words answer the heading on their own, then add the detail. Bing's guidelines ask for the same thing in their own words: "Surface key information early" and "Avoid long introductions before addressing the main topic."
AI bot access
Googlebot renders JavaScript. Most AI crawlers do not. Vercel's measurements across its network found that "none of the major AI crawlers currently render JavaScript," naming OpenAI's OAI-SearchBot, ChatGPT-User and GPTBot, Anthropic's ClaudeBot and PerplexityBot, while Gemini uses Google's rendering. A single-page app that ranks on Google can be an empty shell to ChatGPT.
Access is also per bot. OpenAI separates OAI-SearchBot (search) from GPTBot (training), so you can block training and still be cited. A blanket "block AI" rule in robots.txt or a firewall setting catches both. The deep dive is in the guide on how to optimize for AI search.
Third-party corroboration
Rankings respond to links. AI answers respond more to mentions. In Ahrefs' study of 75,000 brands, branded web mentions correlated with AI visibility at 0.66 to 0.71 across ChatGPT, AI Mode and AI Overviews, and YouTube mentions at about 0.737, while link metrics showed very weak correlations. Ahrefs notes that correlation is not causation, but the pattern is consistent: engines repeat what many independent pages say.
Do you need a separate strategy for each one?
No. One audit covers the foundation for all three, and most fixes serve every engine at once. Work in order: make the site crawlable and indexable, then make key pages answer questions in extractable passages, then earn mentions on other sites. The generative engine optimization explainer covers the GEO layer in more depth.
What does change per engine is the evidence you look for. For Google's AI Overviews specifically, the steps are in how to get cited in Google AI Overviews. For ChatGPT, confirm OAI-SearchBot can reach you. For Copilot, confirm Bing has indexed you, because Copilot grounds in Bing.
How do you measure SEO, AEO and GEO?
Measure SEO in the Search Console Performance report. Measure Google's AI answers in the Search Console generative AI performance report, which counts impressions from AI Overviews and AI Mode and reached all sites on August 31, 2026. Measure Copilot in Bing Webmaster Tools' AI Performance report. For ChatGPT, Perplexity and Claude, run your own questions.
Google organic: clicks, impressions and position per query in the Performance report.
Google AI features: the generative AI performance report shows impressions by page, country and device. An impression there is a link to your site shown inside the AI feature.
Microsoft: the AI Performance report, a public preview since February 2026, shows total citations, average cited pages and the grounding queries Copilot used.
Everything else: write ten questions a buyer asks, run them in each engine, and record whether you are mentioned and linked. The method is laid out in how to measure AI visibility.
Check all three foundations with one scan
Run the free scan on LaunchScaler to check the shared foundation before you work on any single engine. It takes a URL, needs no account and runs 156 checks across 6 of its 7 categories at no cost. The search checks read robots.txt blocks, noindex in the meta tag and the header, canonicals, soft 404s, redirect chains and your sitemap. The AI visibility checks read whether robots.txt or a firewall blocks OAI-SearchBot, Claude-SearchBot or PerplexityBot, whether your main content is missing from the raw HTML, whether your JSON-LD parses and whether your sitemap carries lastmod. Whether engines actually cite you is measured by the full audit ($19 once), which puts 10 questions to 7 answer engines and reads all 70 answers.
No. Google says its generative AI features are rooted in its core Search ranking and quality systems, and Bing says SEO fundamentals also support grounding in Copilot. A page that search engines cannot crawl or index is rarely cited by an answer engine either.
03
Do I need llms.txt or special markup for AEO or GEO?
Not for Google. Its guide to generative AI features says you don't need AI text files, special markup or Markdown to appear in Google Search, including AI Overviews and AI Mode. Other engines publish their own rules, so check each one you care about.
04
Who coined the term generative engine optimization?
The term comes from the paper 'GEO: Generative Engine Optimization' by Aggarwal and colleagues, first posted in November 2023 and published at KDD 2024. It reported that optimization methods could raise a source's visibility in generative engine responses by up to 40%.
05
How do I measure AEO and GEO?
For Google, the Search Console generative AI performance report counts impressions from AI Overviews and AI Mode. For Microsoft, Bing Webmaster Tools has an AI Performance report with citation counts. For ChatGPT, Perplexity and Claude you have to run your own buyer questions and record who gets cited.
Every major AI crawler user agent and robots.txt token, with its operator, purpose, JavaScript rendering and published IP list, checked September 2026.
Vercel measured ChatGPT's crawler spending 34.82% of fetches on 404s and 14.36% on redirects, against 8.22% and 1.49% for Googlebot. How to cut the waste.
