Generative Engine Optimisation (GEO): How to Get Cited by ChatGPT and AI Search in 2026

What is generative engine optimisation?

Generative engine optimisation (GEO), also called AI SEO, answer engine optimisation (AEO), or LLM SEO, is the practice of making your website the source that AI tools use when they answer questions. Instead of competing only for a position in a list of ten blue links, you're competing to be quoted, summarised, or linked in the answer itself.

The term comes from a 2023 research paper, GEO: Generative Engine Optimization, by researchers at Princeton, Georgia Tech, the Allen Institute for AI, and IIT Delhi. They found that specific content changes, notably adding citations, quotations, and statistics, increased a source's visibility in AI-generated answers by up to 40%.

GEO doesn't replace SEO. It builds on it. The same foundations (crawlable pages, fast load times, authoritative content) decide whether AI tools can find you at all.

How AI search engines choose which pages to cite

When someone asks ChatGPT, Perplexity, Gemini, or Google's AI Mode a question that needs current information, the tool typically runs a web search, retrieves a handful of pages, reads them, and writes an answer that cites some of them. This process is called retrieval-augmented generation.

• Retrieval: the tool searches an index (its own, Google's, or Bing's) and picks candidate pages. If you don't rank or aren't indexed, you're not in the running.
• Extraction: it reads the page and pulls out passages that answer the question. Clear, self-contained paragraphs are easier to extract than long, meandering ones.
• Selection: it favours sources that look authoritative, specific, and current, and that agree with other trusted sources.

Google has said that its AI Overviews and AI Mode use the same ranking systems as regular Search, and that no special markup is required to appear in them. In practice, that makes classic technical SEO the entry ticket for AI visibility.

GEO vs SEO: what's actually different

The biggest shift is that AI tools work at the level of passages, not pages. A single well-written paragraph that answers a question precisely can earn a citation even if the rest of the page is about something broader.

Technical GEO: make your site readable by AI crawlers

This is where most sites quietly fail, and where development choices matter more than copywriting.

1. Serve content as HTML. Many AI crawlers fetch the raw HTML and don't execute JavaScript. If your content only appears after a JavaScript app loads in the browser, those crawlers see an empty page. Server-side rendering or static generation (as in Next.js) fixes this. It's also why canvas-rendered web builds, such as Flutter on the web, are a poor fit for content you want found.
2. Allow AI crawlers in robots.txt. Check you're not blocking search-focused bots such as OAI-SearchBot (ChatGPT search), ChatGPT-User, PerplexityBot, and ClaudeBot. Google-Extended controls whether your content trains Gemini, but doesn't affect AI Overviews, which use regular Googlebot.
3. Don't block your CSS and JavaScript files. Search engines need them to render your pages properly.
4. Be indexed in Bing as well as Google. Several AI tools draw on Bing's index, so verify your site in Bing Webmaster Tools and submit your sitemap there too.
5. Keep pages fast and stable. Retrieval happens in real time, and slow or error-prone pages are easy to skip. Good Core Web Vitals help both SEO and GEO.
6. Publish a complete XML sitemap with accurate last-modified dates, so new and updated pages are discovered quickly.

If your current site is a client-rendered single-page app or a slow, plugin-heavy build, a rebuild can be the single biggest GEO win. That's the kind of web app development work where the framework choice directly affects visibility. If you're bringing in outside help, our guide on how to hire a full-stack developer includes the questions to ask about SEO and rendering.

Content GEO: write pages AI tools want to quote

• Answer first. Put a direct, complete answer to the page's main question in the opening sentences, then expand. Our own guides open with a "short answer" box for exactly this reason.
• Define things plainly. "X is a…" sentences are the passages AI tools most often lift for definitions.
• Be specific. Prices, ranges, dates, and named examples are more quotable than general claims. Compare "affordable" with "£50–£120 per hour", the kind of concrete range our full-stack developer cost guide, app development cost guide, and website cost guide are built around.
• Cite your sources. Link to research, official documentation, and primary data. The GEO research found citations and statistics among the most effective changes.
• Use question-based headings that mirror how people ask, then answer each one in a self-contained paragraph.
• Add comparison tables and step-by-step lists. Structured formats are easy to extract and summarise.
• Keep content current. Update figures and the modified date when things change; AI tools favour fresh sources for time-sensitive questions.
• Show experience. First-hand detail (what you built, what you measured, what went wrong) is hard to find elsewhere and signals expertise.

Structured data, entities, and llms.txt

AI tools need to understand who you are, not just what a page says. Three things help:

• Structured data (schema.org JSON-LD): mark up your Organization, Service, Article, FAQPage, and BreadcrumbList so machines can read your business facts and page structure unambiguously.
• Consistent entity facts: use the same business name, address, services, and prices on your website, Google Business Profile, directories, and social profiles. Conflicting facts make AI tools less confident about citing you.
• llms.txt: a proposed standard, published in 2024, for a plain-text file at the root of your site that summarises who you are and links to your key pages in a format language models can read easily.

Be realistic about llms.txt: it's an emerging convention, and the major AI providers haven't confirmed that they use it to choose sources. It takes minutes to create, though, and it gives AI agents a clean summary of your business. You can see ours at unlimiteddev.io/llms.txt, and our complete llms.txt guide covers the format, what Lighthouse checks, and how to control AI crawlers like GPTBot and ClaudeBot.

Build authority beyond your own website

AI answers tend to reflect consensus across many sources. If your business is only described on your own site, there's little for an AI tool to corroborate.

• Get listed in respected industry directories and review platforms for your sector.
• Earn mentions and links from trade publications, partners, and local business organisations.
• Contribute genuinely useful answers in communities where your customers ask questions.
• Collect reviews on platforms that AI tools and search engines already trust.

How to measure AI search visibility

• Referral traffic: in your analytics, look for visits from chatgpt.com, perplexity.ai, gemini.google.com, copilot.microsoft.com, and claude.ai.
• Prompt testing: regularly ask AI tools the questions your customers ask and record whether you're cited, mentioned, or absent.
• Search Console: AI Overviews and AI Mode traffic is included in your Google Search Console performance data, so keep tracking impressions and clicks for your key topics.
• Server logs: check which AI crawlers visit, how often, and whether they receive errors.

GEO checklist

• Key content is server-rendered HTML, visible without JavaScript
• robots.txt allows search and AI crawlers, and doesn't block CSS or JavaScript
• Site verified in Google Search Console and Bing Webmaster Tools, with sitemaps submitted
• Fast pages with healthy Core Web Vitals
• Every key page opens with a direct answer
• Specific facts, prices, and dates, with sources cited
• Question-based headings, tables, and step lists
• Organization, Service, Article, and FAQ structured data
• Consistent business facts across the web
• llms.txt published at the site root
• AI referral traffic and citations tracked monthly

Unlimited Dev builds fast, server-rendered Next.js websites and web apps with technical SEO, structured data, and AI-search readiness built in from the start, whether you're launching an MVP, rebuilding an existing site, or an agency needing white-label development for clients. Agencies can also resell AI-search optimisation this way; see our white-label development guide.

Frequently asked questions