What is generative engine optimisation (GEO)?
GEO is the practice of shaping your content so generative engines like ChatGPT and Perplexity cite it inside their answers. Here is what the term means, how it relates to AEO and SEO, and what the research actually shows.
Generative engine optimisation, usually shortened to GEO, is the newest label for an old goal: being the source an answer is built on. The difference is the surface. Instead of a ranked list of links, the answer is a written paragraph that a generative engine has synthesised, and GEO is the work of getting your content used inside it.
Key takeaway
GEO is the practice of structuring and placing your content so generative engines cite and recommend it inside their generated answers, rather than merely ranking it in a list of links.
What is generative engine optimisation?
GEO is the discipline of improving how often, and how favourably, a generative engine cites your content when it composes an answer. A generative engine is any AI system that retrieves sources and writes a synthesised response over them, such as ChatGPT, Claude, Gemini, Perplexity, Grok, Google AI Overviews or DeepSeek. GEO optimises for that citation, not for a rank.
What counts as a generative engine?
A generative engine is a system that answers a question by retrieving candidate sources and generating prose over them, then citing some of what it used. That covers AI assistants like ChatGPT and Claude, answer engines like Perplexity, and Google AI Overviews sitting on top of classic search. The common thread is that the user reads a written answer, not a page of links.
Is GEO an SEO replacement?
No. GEO sits alongside SEO rather than replacing it. The engines still retrieve live sources, and strong search foundations make you easier to retrieve, so good SEO helps GEO. What changes is the outcome you optimise for and measure: a citation inside an answer, rather than a position in a list.
GEO vs AEO vs SEO: what is the difference?
These three overlap heavily and people use them loosely. The short version: SEO competes for a rank on a results page, while GEO and AEO both compete to be cited inside a generated answer. GEO and AEO are near-synonyms in practice, with GEO the term the research community adopted and AEO the one the marketing world tends to use.
- SEO (search engine optimisation) optimises for position in a ranked list of links, and is measured in rankings, clicks and impressions.
- AEO (answer engine optimisation) optimises for being cited and recommended inside an AI-generated answer, and is measured in citations and share of voice across engines.
- GEO (generative engine optimisation) targets the same outcome as AEO, being used as a source inside a generated response, and is the label coined by the original academic research.
Key takeaway
Treat GEO and AEO as the same job under two names. If you have read our explainer on what AEO is, you already understand GEO.
Is GEO the same as AEO?
For almost all practical purposes, yes. Both describe getting your content cited inside AI-generated answers rather than ranked in a list. GEO comes from academic research and AEO from the marketing community, but the moves, the metrics and the goal are the same. We cover the answer-engine framing in what is AEO.
How is GEO different from SEO?
SEO wins a position in a list of ten links, where the click is the prize. GEO wins a citation inside a single written answer, where being the source is the prize. They share foundations like clear structure and genuine authority, but they measure different outcomes. We break the split down in AEO vs SEO.
Where did the term GEO come from?
The term was introduced in a 2023 research paper, "GEO: Generative Engine Optimization" by Pranjal Aggarwal and colleagues, later accepted to the KDD 2024 conference (arXiv, 2023). The authors, from teams including Princeton and Georgia Tech, coined "generative engine" for AI systems that generate answers over retrieved sources, and "GEO" for optimising to be cited by them.
Who coined the term generative engine optimisation?
The paper by Aggarwal, Murahari, Rajpurohit, Kalyan, Narasimhan and Deshpande introduced both the concept of a generative engine and the GEO acronym (arXiv, 2023). It predates most of the marketing writing on the topic, which is why GEO is the term with a citable academic origin, while AEO grew up in industry blogs.
What did the Princeton GEO study find?
It found that GEO is measurable and that a handful of tactics move the needle. Testing across a benchmark of 10,000 queries, the authors reported that GEO methods can lift a source’s visibility in generative engine responses by up to 40%, with the largest gains from adding quotations, statistics and cited sources (Aggarwal et al., arXiv, 2023).
Which GEO tactics worked best?
On the study’s position-adjusted word-count metric, the three strongest tactics were adding quotations, adding statistics and citing sources, each lifting visibility by roughly 28 to 41% over the no-optimisation baseline (Aggarwal et al., arXiv, 2023). Quotations were the single biggest lever. The through-line is credibility: engines favour content that shows its working with quotes, numbers and references.
Does keyword stuffing help with GEO?
No. The study found that keyword stuffing, the old SEO reflex of packing in relevant terms, offered little to no improvement in generative engine responses and was among the weakest tactics tested (Aggarwal et al., arXiv, 2023). Repetition does not persuade a model that synthesises meaning, so the effort is better spent on substance.
How do you start with GEO?
Start by measuring where you already stand, then work on structure, credibility and off-site presence. The research points at concrete moves: write self-contained answers, back claims with quotes and statistics, cite your sources, and earn accurate mentions in the third-party places engines already trust for your category.
- Structure for extraction. Open each section with a direct answer, use question-shaped headings, and keep one idea per passage so it survives being lifted out.
- Show credibility. Add real quotations, specific statistics and cited sources, the three tactics the study found most effective.
- Skip the old reflexes. Do not keyword-stuff; the research shows it adds little and can read as spam.
- Build off-site presence. Earn an accurate, current presence in the review sites, roundups and communities the engines retrieve from.
- Measure across engines, repeatedly. The same prompt returns different answers run to run, so a single check is noise. Track citations over time.
How Outercite measures GEO
Outercite tracks how AI search engines cite businesses across ChatGPT, Claude, Gemini, Perplexity, Grok and DeepSeek. Rather than trusting a single answer, every candidate citation is checked by a judge model and then confirmed or disputed by an independent verifier model before it counts, so a hallucinated mention is not scored as a real citation.
That two-model check is the point. GEO only compounds if you can tell a genuine citation from noise and prove a change moved the number, which is the discipline the research rewards and the guesswork it replaces.
Sources
- Origin of the term, the 10,000-query benchmark, the up-to-40% visibility lift, the per-tactic ranking (quotations, then statistics, then cited sources, each lifting visibility by roughly 28 to 41% on the position-adjusted word-count metric) and the keyword-stuffing finding: Aggarwal et al., "GEO: Generative Engine Optimization", KDD 2024. arXiv.
