What Is Generative Engine Optimisation (GEO)? How AI Search Affects Your Website

Search is changing faster than at any point in the last decade. Google AI Overviews now appear at the top of millions of search results, summarising answers before users see a single traditional link. ChatGPT's web search feature pulls live content and cites sources. Perplexity.ai has built an entire search engine around AI-generated answers with inline citations. Bing Copilot synthesises results in natural language.

For businesses with websites, this shift raises an urgent question: if an AI engine summarises the answer to your customer's query, will it cite your site — or your competitor's?

That question is what Generative Engine Optimisation (GEO) is designed to answer. The term was formalised in a 2023 Princeton and Georgia Tech research paper that demonstrated systematic differences in which content AI engines select — and how small structural changes to a page can meaningfully increase citation frequency.

> Key Takeaways > > - GEO is the practice of optimising your website content so that AI search engines cite it in generated answers > - AI search selects content at the passage level — individual paragraphs and sentences matter more than overall page rankings > - The main AI search platforms to optimise for are Google AI Overviews, ChatGPT web search, Perplexity, and Bing Copilot > - Key signals include: server-side rendering, citable overview paragraphs, structured headings, clear definitions, E-E-A-T signals, and schema markup > - GEO complements traditional SEO — it does not replace it > - Allowing AI crawlers in your robots.txt is a prerequisite most sites are currently failing

What Is Generative Engine Optimisation?

GEO is the practice of structuring, writing, and technically configuring your website so that AI-powered search engines select and cite your content in their generated answers.

Traditional SEO focuses on ranking a page as high as possible in a list of results. GEO operates differently: the goal is to be the source an AI engine quotes, paraphrases, or links to when it synthesises an answer for a user.

We have implemented GEO across this site. That includes server-side rendering for AI crawlers, an llms.txt file, allowing all major AI crawlers in our robots.txt, citable overview paragraphs on every service page, and question-based headings throughout. This guide shares what we have learned.

How AI Search Differs From Traditional Search

Traditional search: ranking pages

Google's traditional algorithm ranks pages by relevance, authority, and quality signals. A user enters a query, sees a list of blue links, and clicks through. Your goal is to appear as close to position one as possible.

AI search: selecting passages

AI search engines retrieve relevant documents, then generate a synthesised answer by selecting the most useful passages. The output is a paragraph or bulleted summary with citations rather than a ranked list.

The Major AI Search Platforms

Google AI Overviews

Formerly Search Generative Experience (SGE), AI Overviews now appear on an estimated 13–20% of searches, according to industry tracking studies (Semrush's AI Overviews tracking data suggests 13–16% across most markets) — heavily weighted towards informational and how-to queries. They sit above position one, making citation more valuable than traditional first-place ranking in many cases. When a user clicks "Show more," the full AI-generated answer expands with inline source links, making those citation slots even more prominent. Google draws primarily from pages that already perform well in organic search, so GEO and traditional SEO are tightly coupled here.

ChatGPT Web Search

OpenAI's ChatGPT includes live web browsing that pulls current content and surfaces numbered inline citations — similar to academic referencing. Users see source links alongside each claim in the generated answer, making attribution highly visible. It is particularly popular for research, product comparisons, and complex how-to queries where users want synthesised answers rather than a list of links. Millions now use it as a primary research tool, and optimising for ChatGPT citation is increasingly worthwhile for content-heavy service businesses.

Perplexity

Perplexity is built entirely around AI-generated answers with numbered inline source citations and source quality indicators displayed alongside each reference. Its Pro tier has driven significant uptake among professional, academic, and technical audiences who value accuracy and cited evidence. Each answer includes a "Sources" panel showing the full list of referenced pages, making it easy for users to verify and click through — meaning a Perplexity citation can still drive direct traffic. It is growing quickly and is already the default AI search tool for a meaningful segment of professional web users.

Bing Copilot

Bing Copilot is integrated directly into Microsoft Edge and the Windows operating system, giving it a large passive user base beyond active AI search adopters. It draws from Bing's web index and generates conversational answers with footnoted citations at the bottom of each response. Because it relies on Bing's crawler rather than a separate AI-specific bot, traditional Bing SEO signals — backlinks, structured data, content quality — carry over more directly to Copilot citation than on other platforms.

What Makes Content Citable by AI Engines

Clear, standalone definitions

AI engines frequently pull definitional paragraphs that can be dropped into a generated answer without losing meaning. The difference between a citable and non-citable definition often comes down to self-containment. A weak definition might read: "GEO is important for modern SEO and helps websites get found." A strong, citable definition reads: "Generative Engine Optimisation (GEO) is the practice of structuring website content so that AI-powered search engines — such as Google AI Overviews, ChatGPT, and Perplexity — select and cite it in synthesised answers to user queries." The second version works without any surrounding context, which is exactly how AI engines use it.

Specific data and statistics

The Princeton/Georgia Tech GEO research paper found that adding statistics and citations meaningfully improved citation rates — pages with verifiable data were consistently selected more often than those making equivalent claims without supporting evidence. Vague assertions like "most businesses see better results" are far less citable than specific ones backed by data from a named source. Where you cannot cite a primary source, use your own data, client results, or clearly attributed industry research.

Question-based headings

Heading structure is one of the highest-leverage GEO changes you can make. AI queries are predominantly natural language — users ask questions rather than entering keyword strings. When your headings mirror those questions, your content is far more easily matched to the triggering query and extracted as a passage. "GEO Definition" is unlikely to match "What is GEO?" as a query. "What Is Generative Engine Optimisation?" matches it almost exactly. Review your service pages and replace noun-phrase headings with interrogative versions wherever the content is definitional or explanatory.

Authoritative sourcing

Pages that cite credible external sources — government departments (.gov.uk), universities (.ac.uk), established industry publications, or peer-reviewed research — signal to AI systems that the content is factually grounded rather than speculative. This does not mean drowning pages in footnotes. Two or three well-chosen citations per article, linked to primary sources, meaningfully lift credibility signals. It also encourages reciprocal citation behaviour: if you reference a publication, that publication's AI system is more likely to surface you when relevant.

E-E-A-T signals

Google's E-E-A-T guidelines (Experience, Expertise, Authoritativeness, Trustworthiness), introduced in December 2022 and continuously refined, have become a de facto standard that other AI engines appear to follow in spirit. Clear author attribution, verified organisational identity, and factual accuracy all contribute to whether a passage is treated as a reliable source. Author bios with genuine credentials, a clear About page, and consistent NAP (name, address, phone) data across the web all strengthen E-E-A-T. These signals also directly improve traditional SEO, reinforcing why GEO and SEO are complementary strategies.

Practical GEO Tactics

1. Allow AI crawlers in robots.txt

If your robots.txt blocks AI crawlers, those engines cannot read your content and cannot cite it — it is a hard exclusion. The key user agents to explicitly allow are `GPTBot` (OpenAI), `OAI-SearchBot` (OpenAI's search variant), `ClaudeBot` (Anthropic), `PerplexityBot` (Perplexity), and `Googlebot` (Google, including AI Overviews). A correctly configured robots.txt entry looks like this:

User-agent: GPTBot
Allow: /

User-agent: OAI-SearchBot Allow: /

User-agent: ClaudeBot Allow: /

User-agent: PerplexityBot Allow: / ```

Check your current robots.txt at `yourdomain.com/robots.txt`. Many sites inherited blanket Disallow rules from older configurations and are unknowingly blocking AI crawlers across the entire site.

2. Use server-side rendering (SSR)

JavaScript-heavy frameworks like React render content client-side by default — meaning the server sends an almost empty HTML document, and the browser builds the page using JavaScript. Most AI crawlers cannot execute JavaScript. When they visit a client-rendered page, they see a near-empty shell with no indexable text and therefore nothing to cite. Next.js solves this by rendering HTML on the server before it reaches the crawler, making all content immediately visible in the page source. Googlebot can execute JavaScript given time, but Perplexity's crawler, ClaudeBot, and GPTBot typically cannot — making SSR non-optional for any serious GEO strategy.

3. Publish an llms.txt file

`llms.txt` is an emerging convention (not yet a universal standard) that places a plain-text file at the root of your domain — `yourdomain.com/llms.txt` — to give AI models a structured summary of your site. The format is straightforward: a brief description of your organisation, a list of your most important pages with one-line summaries, and an indication of the content types available (guides, case studies, service pages, blog posts). It does not guarantee citation, but it provides AI crawlers with a navigational map they can use when they are trying to understand what your site covers. Think of it as an XML sitemap, but written for AI models rather than search engines.

4. Write citable overview paragraphs

Every service page and pillar content piece should open with a 130–170 word overview paragraph that stands alone as a complete, citable description — no assumed context, no marketing fluff. The contrast between a vague and a citable paragraph is stark. Vague: "We offer brilliant web design services that help businesses grow online and stand out from competitors in a crowded digital market." Citable: "Brambla designs and builds custom websites for UK small businesses, typically delivering projects in 7 days (7 Day Website) or 4–6 weeks (Custom Website). Our web design service covers UX planning, copywriting, brand-consistent visual design, and technical build — with all sites hosted on managed UK infrastructure and covered by an ongoing SiteCare maintenance plan." The second version can be extracted by an AI engine and still communicate clearly without any surrounding context.

5. Use question-based headings

The mechanism is simple: AI queries are phrased as natural language questions, and AI engines match those queries to headings and passages that share the same phrasing. If a user asks "How long does a website take to build?" and your page has a heading "Our Build Process," the match probability is low. If your heading reads "How Long Does It Take to Build a Website?", the match is direct. Review every service and guide page and convert descriptive noun-phrase headings ("Benefits," "Our Approach," "Key Features") into interrogative equivalents ("What Are the Benefits?", "How Do We Approach This?", "What Features Are Included?"). This single change can meaningfully increase extraction frequency across all AI platforms.

6. Implement structured data (schema markup)

Schema markup provides AI systems with unambiguous, machine-readable metadata about your content — who wrote it, when it was published, what organisation it belongs to, what questions it answers. The most important schema types for GEO are: `Organization` (company identity, contact details, founding date), `Person` (author credentials and social profiles), `Article` or `BlogPosting` (publication date, author, topic), `FAQPage` (question-answer pairs that AI engines extract directly), and `Service` (what you offer and at what price). JSON-LD is Google's preferred format and the most widely supported by AI engines — it lives in a `<script>` tag in the page head rather than being embedded in the HTML body, keeping it clean and parseable.

7. Build brand mention signals

Brand mentions across credible third-party sources build an off-page signal that your organisation is real, established, and trusted. AI engines aggregate signals from across the web, not just from your own domain. Practical ways to build mentions include: guest articles in industry publications, listings in established directories (Clutch, DesignRush, local chamber of commerce sites), partnership and case study mentions on client sites, and press coverage. Each mention reinforces the pattern that your brand is a legitimate source on its topic area. Over time, this off-site signal compounds — AI engines become progressively more likely to surface you when your area of expertise is queried.

GEO and Traditional SEO: Complementary, Not Competing

Traditional SEO remains essential. High-intent commercial queries still return ranked results, and position one still captures the majority of clicks. The strategies in our small business SEO guide remain the foundation.

GEO extends that foundation into a new channel. Some businesses are discovering that AI Overviews reduce click-through rates — making it even more important to be the cited source. We cover this in our post on AI-generated websites and SEO problems. We also look at how AI search is reshaping local business discovery and what small businesses can do practically to improve their AI visibility.

Our SEO Care service now includes GEO implementation as standard. If you are building or redesigning your site, our web design service bakes GEO-ready technical foundations in from the start.

Measuring GEO Impact

GEO results are harder to quantify than traditional SEO rankings, but a structured monitoring approach gives you a clear picture of where you stand and how you are improving over time.

Tools for GEO monitoring

Manual query testing is the most direct method: search your target queries in ChatGPT, Perplexity, and Google AI Overviews and record whether your site is cited, where in the answer, and which page is referenced. Do this monthly for your ten most important queries and track changes over time.

Google Search Console is adding AI Overview impression data progressively — filter by queries that show high impressions but low CTR, which often indicates an AI Overview is absorbing clicks that would otherwise land on your page. Being the cited source in that Overview restores the visibility.

Brand24 and Mention monitor web-wide brand citations, including in AI-generated content that gets republished or shared. These tools surface mentions you would otherwise miss and give you a sense of citation velocity over time.

Setting realistic expectations

GEO results compound over months, not days. Unlike a rankings change that can appear within a crawl cycle, GEO citation depends on AI engines building confidence in your content through repeated positive signals — crawl history, external mentions, structured data, and content quality all accumulating together. Most sites see meaningful improvement in citation frequency within three to six months of implementing the tactics above.

It is also worth noting that Google AI Overviews are still evolving. Google regularly adjusts which query types trigger an AI Overview and which return standard results. A query that triggers an Overview today may not do so in three months — and vice versa. Build a GEO strategy around content quality and technical foundations rather than chasing specific query patterns, and the results will be more durable. Our pricing page includes GEO implementation as part of our SEO Care plans.

Related Reading

• Is My Business in ChatGPT? How to Check (And What to Do If It's Not)
• GEO vs SEO: What's the Difference and Do You Need Both?
• AI Visibility for Small Businesses: A Practical Guide
• How AI Search Is Changing Local Business Discovery
• SEO for Small Businesses in the UK: Where to Start
• Website Content Writing for SEO: A Practical Guide for Business Owners
• Why AI-Built Websites Struggle with SEO (And How to Fix It)

Frequently Asked Questions

What is the difference between GEO and SEO?

Traditional SEO focuses on ranking pages in search results. GEO focuses on getting your content cited by AI-powered search engines in their generated answers. They complement each other.

Does GEO replace traditional SEO?

No. Traditional SEO remains essential for commercial queries, local search, and direct organic traffic. GEO extends your presence into AI-generated answers.

How do I know if AI search engines are crawling my site?

Check server access logs for GPTBot, ClaudeBot, PerplexityBot user agents. Test your robots.txt to confirm these bots are allowed.

How long does it take for GEO changes to have an impact?

Allow four to twelve weeks. Google AI Overviews reflect Googlebot's crawl schedule. Perplexity and ChatGPT update on varying schedules.

Start Getting Cited by AI Search Engines

Our SEO Care service includes GEO optimisation as standard. If you are not sure where to start, a Website Audit will give you a clear picture of where your site currently stands.

Related Reading

• E-E-A-T for SEO: How to Build Trust Signals That Google Actually Measures
• Topical Authority: How Content Clusters Help You Rank Higher
• **Complete Guide:** AI Visibility & GEO: The Complete Guide for UK Small Businesses