AI and search: SEO, AEO and GEO explained
Search is changing: instead of a list of links, Google, ChatGPT and Perplexity now often write the answer for you. That's handy for searchers but a big shift for anyone with a website. Here's how AI search works, what the numbers say, how SEO, AEO and GEO differ, what to do about it and why website owners are pushing back against AI crawlers.
Search then vs search now
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You click a few links and read them yourself.
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AI answer
123 sources
The answer is written for you. Fewer people click through.
- 1 billion+monthly users of Google's AI Mode, one year after launchblog.google
- 8% vs 15%how often people clicked a result link with an AI summary on the page, compared with without onepewresearch.org
- 1%of visits where people clicked a link inside the AI summary itselfpewresearch.org
- Up to 500,000 : 1pages one AI company's bots crawled for every visitor it sent back to websites, at its 2025 peakblog.cloudflare.com
Where AI answers come from
Most AI search tools work the same way: they search the web, pick a handful of pages, and write a summary from them with links (a technique called RAG). So being one of the pages they pick is what matters now.
- Google AI Overviews and AI ModeAn AI summary at the top of search results, or a full chat-style search, with links to sources.
- ChatGPT searchChatGPT searches the web when needed and answers with cited links.
- PerplexityAn "answer engine" that writes a short answer from several sources, with numbered citations.
- Gemini, Copilot and ClaudeAI assistants that can search the web for up-to-date answers.
SEO vs AEO vs GEO: what's the difference?
Three names for overlapping jobs. Good SEO is still the foundation; AEO and GEO build on it for the AI era.
| SEO | AEO | GEO | |
|---|---|---|---|
| Stands for | Search engine optimisation | Answer engine optimisation | Generative engine optimisation |
| The goal | Rank high in the list of search results | Be the direct answer to a question | Be quoted or cited inside AI-written answers |
| Where you appear | The "10 blue links" | Featured snippets, "People also ask", voice assistants | AI Overviews, ChatGPT, Perplexity, Gemini |
| What helps | Useful content, keywords, links from other sites, a fast and crawlable site | Clear questions and short, direct answers; FAQs; structured data | Facts, statistics, quotes and sources; clear structure; a trusted, well-known brand |
| Success looks like | Clicks and visits | Your answer shown (often without a click) | Your brand or page mentioned and linked by AI |
GEO was named in a 2023 research paper from Princeton and others (arXiv). Google says there are no special requirements to appear in its AI features beyond normal SEO best practices.
What to do (and what not to)
Do
- Write genuinely useful, original content: Google says the usual SEO best practices still apply to its AI features, with no special tricks needed.
- Answer the question early and clearly, then add detail below.
- Back claims with facts, statistics, quotes and sources. Researchers found this kind of content can be up to 40% more visible in AI answers.
- Use clear headings, lists and tables, and add structured data where it fits.
- Keep pages fast and crawlable, and show who wrote them and why they can be trusted.
- Track visits from AI tools as well as from search, since clicks are falling.
Don't
- Mass-produce thin pages with AI: Google treats this as "scaled content abuse" and spam.
- Stuff keywords: it doesn't help with AI answers and can make pages worse.
- Pay for "guaranteed AI ranking" services: nobody controls what AI engines cite.
Source: Google spam policies
The AI crawling problem
AI tools need web pages to learn from and to answer questions. Website owners pay for the servers those bots use, but get fewer visitors back. Here's the tension, and what's being done.
- Take a lot, give little backAI companies' bots read huge numbers of pages but send few visitors in return. In 2025 Cloudflare measured one AI company crawling up to 500,000 pages per visitor sent; for Google Search the figure was roughly 3 to 30.Source: blog.cloudflare.com
- Publishers push backRolling Stone's owner, Penske Media, sued Google in 2025, saying AI Overviews used its articles while cutting its traffic and affiliate revenue by more than a third. A judge dismissed that case in October 2026, but the fight over payment continues.Source: axios.com
- New controls for site ownersCloudflare now blocks AI crawlers by default unless a site allows them, and is testing "pay per crawl". Google offers a "Google-Extended" setting to keep content out of Gemini training, but it does not affect Search or AI Overviews.Source: developers.google.com
- A sign-post for AI: llms.txtA proposed /llms.txt file gives AI tools a clean summary of a site, first suggested by Jeremy Howard in 2024. It is still a proposal, not an official standard.Source: llmstxt.org
How we chose the evidence
We relied on Google’s own documentation and announcements, the Pew Research Center, Cloudflare’s network data and the original GEO research paper, plus reliable news coverage of the publisher lawsuits. AI search changes quickly, so we review this page every quarter. For more on AI bots, see AI and cyber security; for how AI looks things up, see RAG.