Glossary // Generative engine optimization
What Is Generative Engine Optimization (GEO)? Origin, Methods and Limits (2026)
Updated
Generative engine optimization (GEO) is the practice of making content more likely to be used and cited by generative engines: AI systems that answer a query by retrieving sources and writing a response from them. ChatGPT search, Perplexity, Google AI Overviews and AI Mode, and Microsoft Copilot are all generative engines in this sense. Where SEO tries to earn a position in a list, GEO tries to earn a place inside the answer, usually as a cited link.
Where the term comes from
The name comes from a 2023 research paper, GEO: Generative Engine Optimization (arXiv 2311.09735). It treated generative engines as a new kind of search system, one that combines retrieval with a language model and returns a synthesized answer, and asked what content creators can do about their visibility inside those answers. Because the paper gave the field its name, GEO became the research-flavoured label, while the search industry mostly says answer engine optimization.
GEO, AEO and SEO
The three labels overlap more than their advocates admit:
- SEO gets a page indexed and ranked. Without it, nothing else applies.
- AEO and GEO get a page chosen as a source for a written answer. Google states that eligibility for AI Overviews and AI Mode is the same as ordinary Search eligibility with a snippet, and that there are no additional technical requirements.
- What is genuinely new is the set of decisions around AI crawlers (training versus search versus user-requested fetches), preview controls that limit how much an answer may quote, and measuring citations rather than rankings.
What the studies actually measured
GEO is full of confident percentages, so it helps to know what the better studies counted.
Citation accuracy. A Stanford audit of four generative search engines (Liu et al.) found that only 51.5% of generated sentences were fully supported by their citations, and only 74.5% of citations supported the sentence they sat beside. The authors also found citation precision was inversely correlated with how useful people rated the answers. The Tow Center later asked eight AI search tools to identify the source of news excerpts; collectively they answered more than 60% of queries incorrectly. Both audits are summarised in how often AI search engines cite the wrong source.
Clicks. Pew found users clicked a traditional result in 8% of visits with an AI summary against 15% without one; Ahrefs modelled about a 34.5% drop in position-one CTR on desktop; Seer found AI Overviews tend to appear on queries that already drew fewer clicks; Semrush found zero-click rates on the same keywords fell slightly after AI Overviews appeared. Four methods, four answers.
First-party data. Bing's AI Performance report counts citations, cited pages and grounding queries directly; Google folds AI features into the Web search type in Search Console. That gap means most GEO reporting outside Bing is your own sampling. The two reports are compared in what first-party data shows about AI search.
What GEO work looks like in practice
- Make every important page citable. Indexed, crawlable, text-first, with the answer to its main question in the first sentence of the relevant section.
- Decide AI crawler access on purpose. Search crawlers such as OAI-SearchBot, PerplexityBot and Claude-SearchBot decide whether you can appear in those engines; training crawlers such as GPTBot and ClaudeBot do not.
- Treat llms.txt as a guide for agents, not a ranking lever. Worth it on documentation sites, optional on most others.
- Measure with a fixed question set. Pick the questions that matter, run them on a schedule, and log which URLs are cited, the way you would run an LLM eval: same inputs every time, scored the same way.
A prompt for tracking your own citations
The Tow Center's method is easy to copy for your own content. Paste a distinctive excerpt from one of your pages into an AI search tool with this prompt:
Here is an excerpt from a published web page: "[paste 2-3 sentences]".
Identify the original page: give its headline, the publisher, the publication date and the URL.
If you are not certain, say so instead of guessing, and list the candidates you considered.
Score the headline, publisher and URL separately, as the study did, and click every URL. A citation that names you and then links to a syndicated copy or a broken page is a GEO problem worth knowing about. Once you have a few weeks of results, the ChatGPT prompts for data analysis pack helps turn the log into a readout.
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Questions
Where does the term GEO come from?
From a 2023 research paper, "GEO: Generative Engine Optimization" (arXiv 2311.09735), which framed generative engines as a new kind of search system that writes answers from retrieved sources and asked how content creators can improve their visibility in those answers.
What is the difference between GEO and SEO?
SEO aims for a ranked position in a list of results. GEO aims for a page to be used and cited inside a written AI answer. In practice they share most of their foundations: Google says a page needs to be indexed and eligible for a snippet to be cited in AI Overviews or AI Mode, with no additional technical requirements.
Is GEO the same as AEO?
Close enough that most people use them interchangeably. GEO is the research label from the 2023 paper; AEO, answer engine optimization, is the label the search industry adopted. Both describe getting cited in AI answers.
Can you measure GEO?
Partly. Bing Webmaster Tools reports citations in Copilot and Bing AI summaries. Google counts AI Overviews and AI Mode inside overall Search Console Web traffic without separating it. For ChatGPT, Perplexity and Gemini you have to run the questions yourself and log the cited URLs.
Does GEO work?
Some tactics can change how often a page is cited in controlled tests, but the systems change often and their citations are frequently inaccurate. Treat any single study, including vendor studies, as a starting hypothesis to test on your own pages.
Related terms
Glossary
Answer engine optimization
Answer engine optimization (AEO) is the work of making a page easy for AI answer engines like Google AI Overviews, ChatGPT search and Perplexity to fetch, understand and cite as a source.
Glossary
llms.txt
llms.txt is a proposed markdown file, usually at /llms.txt, that gives language models and AI agents a short curated guide to a site's content: a title, a summary, and annotated lists of links.
Glossary
LLM evals
LLM evals are repeatable tests that run a model, prompt, or agent on a fixed set of inputs and score the outputs against stated criteria, so that a change can be measured instead of guessed at.
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