GEO (Generative Engine Optimization): what it is and how it works

When you search for something on Google, it is increasingly common for the first answer not to be a list of ten blue links but an AI-generated paragraph that already sums up what you need to know, with a few sources cited underneath. The same happens if you ask ChatGPT or Perplexity directly: instead of sending you off to search, they answer you. That shift in behaviour has a name inside the digital marketing industry: GEO, or Generative Engine Optimization.

In this guide you will find:

• What GEO is and where the term comes from.
• How it resembles traditional SEO and how it differs from it.
• How generative engines such as ChatGPT or Google’s AI Overviews “read” your content.
• What changes in practice for a marketing team that wants to adapt.

What is GEO (Generative Engine Optimization)?

GEO is the set of practices aimed at getting your content retrieved, understood and cited by generative search engines: systems such as ChatGPT, Perplexity, Gemini or Google’s AI Overviews, which do not just list pages but synthesise an answer from several sources.

It is not a marketing label with no origin. The term was coined in a specific academic study, which gives it a verifiable starting point that is unusual in this industry.

Where the term comes from

GEO was formalised in the paper “GEO: Generative Engine Optimization”, published by a team of researchers from Princeton University and other institutions (Aggarwal, Murahari, Rajpurohit, Kalyan, Narasimhan and Deshpande) and presented at the ACM’s KDD 2024 conference. The study built its own benchmark, called GEO-bench, with thousands of real queries to measure how visible a piece of content is inside AI-generated answers, and tested different optimisation techniques (adding citations, including statistics, using more authoritative language) against that benchmark.

The figure most often repeated from the study is that the most effective techniques achieved improvements of up to 40% in visibility. Some precision is needed here: that is a maximum, not an average, measured against a metric specific to the study itself (the position and proportion of a source’s words cited within the generated answer), and the benefit was greater for sources starting from a low position. It is not a promise that any content will improve by 40% with the same techniques.

GEO vs SEO: what they share and what they do not

The question that comes up most is whether GEO replaces SEO. The short answer is no: they share the same technical foundation but pursue a different goal. Traditional SEO aims to get your page high up a list of results. GEO aims to make your content the source a generative system chooses to cite or synthesise inside its answer.

What classic technical SEO still requires

None of this has stopped being relevant:

• That crawling is allowed (robots.txt, HTTP headers, a WAF with no accidental blocks).
• Indexable, readable content that does not depend on JavaScript to show up.
• A clear heading structure and site architecture.
• Authority and trust in the source (what classic SEO calls E-E-A-T).

In fact, Google is explicit about this: it requires no special markup or techniques to appear in AI Overviews or AI Mode, and points straight back to the same technical SEO fundamentals as always, starting with crawling being allowed.

What GEO adds

On top of that same technical foundation, GEO adds a layer of work designed specifically around how a language model processes and synthesises content:

• Structure built for snippet extraction: direct answers at the start of each section, not at the end.
• Explicit authority signals: data, sourced figures and verifiable claims, not just keywords.
• Factual clarity: drawing a precise line between a confirmed fact and an opinion or an industry trend.
• Specific accessibility for each AI assistant’s crawlers, which are not always the same ones used by traditional search engines.

Aspect	Traditional SEO	GEO
End goal	A position in a list of results	Being the source cited or synthesised in an answer
Unit being assessed	The whole page	Often the specific snippet or paragraph
Technical foundation	Crawling, indexing, authority	The same, plus structure for extraction
Measurement	Rankings, CTR, organic traffic	Whether and how often you are cited (no single standard yet)

How generative engines “read” content

Behind an answer from ChatGPT, Perplexity or an AI Overview there is usually a two-step mechanism: retrieval and generation. First, the system searches for and selects a set of sources relevant to the question (much as a traditional search engine selects results). Then a language model synthesises those sources into a written answer, citing or linking to some of them.

This has a direct practical consequence: if your page is not accessible to the crawler feeding that first step (because of a robots.txt block, a noindex header or content that only renders with JavaScript), it never reaches the retrieval stage, however well written the content is.

One nuance that tends to cause confusion, and that answers the question of how to block GPTBot without losing visibility in ChatGPT directly: OpenAI runs several different crawlers, each controlled separately from robots.txt.

# Block only the training of OpenAI models
User-agent: GPTBot
Disallow: /

# Allow ChatGPT to cite your content in searches
User-agent: OAI-SearchBot
Allow: /

# Allow ChatGPT to visit your page when a user asks for it directly
User-agent: ChatGPT-User
Allow: /

GPTBot crawls content to train OpenAI’s models. OAI-SearchBot is the crawler that lets your site appear when someone searches inside ChatGPT. ChatGPT-User is the one that kicks in when a user asks ChatGPT to look at a specific page. Blocking the first is a legitimate editorial decision (you do not want your content training third-party models); blocking the other two has a real visibility cost, because they are the ones that let you appear cited.

From SEO to GEO: what changes in practice for a marketing team

Moving from SEO to GEO does not mean learning a new discipline from scratch. For a marketing team that already runs SEO, the practical change comes down to three fronts:

• Accessibility for AI crawlers: review robots.txt and HTTP headers not just with Googlebot in mind but with each AI agent separately, because default policies vary between providers.
• Content readability: check that the key information does not depend on JavaScript to render, since many of these crawlers do not run scripts the way a browser would.
• Consistent brand presence: make sure the data, figures and claims about your business are consistent across your site, your profiles and other mentions, because a generative system synthesises from several sources at once.

This is a starting point, not a complete technical checklist: each of these fronts deserves an article of its own with more implementation detail.

Checking whether your site has any of these baseline problems (an accidental robots.txt block, content that does not render without JavaScript, an unclear heading structure) is exactly the kind of technical diagnostic offered by Parsigo’s engine, assessing accessibility, readability and structure in a verifiable way. It is not a guarantee that an AI assistant will cite you (nobody can promise that from the outside), but a technical check of whether your site is, at the very least, in a fit state to be read.

GEO does not replace SEO, it extends it

GEO is neither a passing fad nor a label for selling the same old thing under a new name, but nor is it a discipline that replaces technical SEO: it is an extra layer on top of the same fundamentals (crawling allowed, accessible content, real authority), designed for a moment when more and more people get AI-generated answers instead of lists of links.

If you want the logical next step after understanding what GEO is, check for free whether your site is accessible to AI crawlers before investing time in optimising content they cannot even read.

Frequently asked questions about GEO

What is GEO in digital marketing?

GEO (Generative Engine Optimization) is the set of practices for getting your content retrieved, understood and cited by generative search engines such as ChatGPT, Perplexity or Google’s AI Overviews, rather than appearing only as a link in a traditional list.

What is GEO in SEO?

Within SEO, GEO is the extension of traditional optimisation practices into an environment where answers are generated and synthesised with AI. It shares the same technical foundation as classic SEO (crawling, indexing, authority) but adds specific work on structure and factual clarity designed around how a language model processes content.

What is the difference between traditional SEO and GEO?

Traditional SEO aims to rank your page in a list of results. GEO aims to make your content the source a generative system cites or synthesises inside an answer. The technical fundamentals (crawling allowed, accessible content, authority) are the same in both cases.

How do GEO and AEO differ?

In practice the two terms are often used interchangeably and overlap a good deal: AEO (Answer Engine Optimization) tends to focus on optimising for direct questions (featured snippets, People Also Ask, voice assistants), while GEO was born specifically tied to visibility inside LLM-based generative search engines. In many cases, the techniques that improve one also improve the other.

What is the best tool for GEO?

There is no objective answer today: the market for GEO- and AEO-specific tools is still maturing, and “best” depends on what you need to measure (technical accessibility, presence in AI answers, content structure). Before picking a tool, it is worth being clear about which part of the problem you want to solve first.