GEO, generative engine optimization, is the work of getting your pages selected and cited inside AI generated answers on ChatGPT, Claude, Perplexity, Gemini and Google's AI Overviews and AI Mode. SEO gets you ranked and clicked in a list of links. The crawling, indexing and quality foundation is the same, but the unit of success moves from a ranking position to a citation, and the content that earns a citation is not always the content that earns a click.

What is GEO, and how is it different from SEO?

The term comes from a 2023 paper by Aggarwal, Murahari and colleagues, published at KDD 2024, which defined generative engine optimization as optimizing content "to boost visibility in generative engine responses" and reported gains of up to 40% on their benchmark (arXiv). The generative engine retrieves a set of pages, reads them, and writes one answer with citations. Your page is either in that answer or invisible.

That changes the shape of the competition. In classic SEO, ten results share a page and position three still gets traffic. In an AI answer, a few sources get named and the rest are not shown at all.

SEO GEO
Goal Rank and get the click Be retrieved, quoted and cited
Unit of success Position for a query Citation inside an answer
First reader A person scanning titles A model scanning passages
What wins Relevance, links, intent match Clear claims, evidence, quotable sentences, an unambiguous entity
Main report Search Console clicks and position Search Console generative AI impressions, citation checks per engine

What stays the same?

More than most vendors admit. Google states there are "no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary", and that a page must simply be indexed and eligible to show with a snippet (Google, AI features and your website). Its May 2026 guide adds that you do not need "new machine readable files, AI text files, markup, or Markdown", that an llms.txt file neither harms nor helps, and that "Structured data isn't required for generative AI search" (Google, optimizing for generative AI).

The other engines are built on crawlers that behave like search crawlers. OpenAI's OAI-SearchBot exists "to surface websites in search results in ChatGPT's search features" (OpenAI), and PerplexityBot "is designed to surface and link websites in search results on Perplexity" (Perplexity). If a page cannot be fetched and parsed, no engine can cite it. Crawlability, clean HTML, fast pages and real expertise still come first.

What changes when a model writes the answer?

Three things change, and each one shifts how you write.

The query is not one query. Google describes AI Mode as "breaking down your question into subtopics and issuing a multitude of queries simultaneously on your behalf" (Google). Ranking for the head term matters less than covering the subquestions a buyer would actually ask, each with a direct answer on the page.

Selection is stricter and synthesis is short. Pew's study of 68,879 real searches found the median AI summary ran 67 words and cited three or more sources 88% of the time. Wikipedia, YouTube and Reddit together supplied 15% of the cited links, and government sites 6% versus 2% in standard results (Pew Research Center). The model rewards pages it can trust and lift from in one pass.

Evidence outranks keywords. In the GEO paper's tests, adding quotations raised position-adjusted visibility by 41%, adding statistics by 33% and citing sources by 28%, while keyword stuffing cut it by 9%. Run on Perplexity itself, quotations gave a 22% lift and statistics 37% on the subjective impression score (Aggarwal et al.). The old habit of repeating the target phrase actively hurts.

Which crawlers matter for GEO?

Each vendor now splits its bots, and the split decides whether you can be cited at all.

Platform Search or indexing bot Training bot User fetcher
OpenAI OAI-SearchBot GPTBot ChatGPT-User
Anthropic Claude-SearchBot ClaudeBot Claude-User
Perplexity PerplexityBot none documented Perplexity-User
Google Googlebot Google-Extended (a control token) n/a

OpenAI says disallowing GPTBot "indicates a site's content should not be used in training generative AI foundation models" and manages OAI-SearchBot separately (OpenAI). Anthropic warns that disabling Claude-SearchBot "may reduce your site's visibility and accuracy in user search results" (Anthropic). Google-Extended "does not impact a site's inclusion in Google Search nor is it used as a ranking signal" (Google). The full robots.txt is in our AI crawlers guide.

How do you measure GEO?

Not with sessions. Ahrefs compared 300,000 keywords in December 2023 and December 2025 and found a 58% lower average clickthrough rate for the top-ranking page when an AI Overview was present, up from the 34.5% gap it measured in its March 2024 to March 2025 comparison (Ahrefs, 2025) (Ahrefs). Traffic can fall while your visibility rises.

Since August 31, 2026, Search Console shows a dedicated generative AI performance report for every site, with impressions, pages, countries and devices for AI Overviews and AI Mode, but no clicks or queries (Google, Search Console Help). Pair it with a fixed list of buyer questions you run through each engine every month, recording whether you are cited and which URL appears. We cover the full scorecard in what to measure instead of organic traffic.

Where should a company start?

In this order: confirm every search and user-fetch bot can reach the pages that matter, answer the buyer's question in the first paragraph of each page, add one original number or quote per section with its source, and mark up the organization and author so the entity is unambiguous. Then fix the pages that already rank but are never cited, because they are closest to the line.

This is the sequence Qubba Marketing runs for partners, and it is mostly editing, not rebuilding. The pages that win citations tend to be the ones that state a fact plainly and back it up.

Frequently asked questions

Does GEO replace SEO?

No.
Google's guide states that optimizing for generative AI search "is optimizing for the search experience, and thus still SEO", and every AI engine relies on a crawler that needs the same access and clarity a search crawler needs.
GEO is the extra layer on top: quotable claims, evidence, entity clarity and citation tracking.
Skip the foundation and nothing above it works.

Do I need an llms.txt file for GEO?

Not for Google.
Its guide says such files "neither harm nor help your site's visibility or rankings" because Google Search does not use them.
No other major engine documents reading llms.txt either.
It costs little to publish one, but treat it as a courtesy for tools that may read it, not as a ranking or citation signal.

Is GEO the same as AEO?

Answer engine optimization and generative engine optimization describe the same work from different angles: getting cited inside a generated answer rather than ranked in a list.
Google addresses both labels together and concludes the practice is still SEO.
Pick one name internally and measure it with citations and AI impressions, not with the label.

How many sources does an AI answer cite?

Usually a few.
Pew's analysis of Google AI summaries found 88% cited three or more sources and only 1% cited a single source, with a median summary length of 67 words.
That is why being retrievable is not enough: your page has to be one of the few the model chooses to name, on the specific question being asked.