GEO vs SEO: what's different and what stays the same.
SEO earns a page a position in a list of search results. GEO, generative engine optimization, earns a brand a place inside the one answer an AI engine writes, and a link among the few sources it cites. The groundwork carries over: a crawlable, indexed site that answers questions plainly. What changes is how the system chooses, what counts as a win, and how you measure it, because a generated answer is a sample, not a fixed ranking.
What is the difference between GEO and SEO?
SEO optimizes for a ranking system that orders pages. GEO optimizes for a generative engine, such as ChatGPT, Perplexity, Claude or Google AI Overviews, that reads sources and writes a new answer each time. In SEO the page is the unit and its position is the score. In GEO the brand is the unit, and the score is how often the answers name it, how they describe it and which pages they cite.
| Dimension | SEO | GEO |
|---|---|---|
| Goal | Rank a page high in the results for a query. | Get your brand named, described correctly and cited inside the answer a generative engine writes. |
| Unit of success | A position and a click on one URL. | A mention, where it sits in the answer and a cited link, counted as a rate across many answers. |
| How the system chooses | Ranking systems order indexed pages for the query and show a list of results. | The engine either searches, often splitting the question into several searches, and synthesizes one answer from the sources it read, or answers from what its model learned in training. |
| Signals | Whether the page is indexable, how well it answers the query, and the links and quality signals search engines document. | What the sources the engine reads say about you, most of them third-party lists, reviews and comparisons; whether each engine's crawler can read your pages; whether the model can tell which company you are. |
| What to measure | Impressions, clicks, average position and indexed pages. | Mention rate per engine with an interval, who is named instead, which pages are cited, and whether the description is right. |
| Cadence | Trends read weekly or monthly. | Repeated sampling: the same questions asked on a schedule, because one generated answer is one draw. |
| Tools | Google Search Console, Bing Webmaster Tools, rank trackers and site crawlers. | AI visibility tools that ask engines your buyer questions on a schedule; see the tools compared on sourced facts. |
What carries over from SEO to GEO?
Most of the technical floor, and Google says so directly.
- Indexing and eligibility. Google's guidance on its AI features says the best practices for SEO remain relevant for AI Overviews and AI Mode, that a page must be indexed and eligible to show with a snippet to be a supporting link, and that there are no additional technical requirements.
- No special files. The same page says you don't need new machine readable files, AI text files or markup to appear in those features.
- Crawler access, with more crawlers. robots.txt and CDN rules still decide who can read you, but each engine has its own bots. OpenAI documents that sites opted out of OAI-SearchBot will not be shown in ChatGPT search answers, whatever Googlebot is allowed to do.
- Clear, current pages. An answer in the first sentence under a heading that asks the question, and facts in the HTML rather than added later by JavaScript, help a search snippet and a generated answer alike.
- Reputation off your site. Reviews, listings and coverage mattered for SEO. For GEO they matter more, as the next section shows.
What is different about GEO?
The sources skew to other people's pages. A University of Toronto study (Chen and colleagues, September 2025) compared the domains AI search and Google returned for the same ranking questions. For software products in the US, AI search returned 72.7% earned sources, meaning independent media, review and comparison sites, and 26.7% brand sites. Google returned 43.7% brand, 45.4% earned and 10.9% social. We summarize it in who gets cited next to you. Proofsource's own count points the same way: across 13,386 citations in 1,205 answers to unbranded buyer questions, eight tracked competitors' websites took 16% and the brand's own site 0.87% (the full count, by engine).
Engines disagree with each other. SEO mostly answers to one search engine. GEO answers to several, and they choose differently. When Proofsource asked four engines the same 292 buyer questions on the same days, all four named the brand on only 32% of the question days where at least one did, and 30% of the tracked names came from a single engine (four engines rarely name the same brands).
Sometimes nothing is retrieved at all. A generative engine can answer from what its model learned, with no search and no ranking step. In a Proofsource sample of 364 answers, ChatGPT named the brand in 78% of the answers where it searched the web and 6% where it didn't, and two thirds of its answers never searched (check whether the engine searched at all). No ranking report can see that half of the picture.
The answer moves from day to day. Rankings drift; answers churn. Asking the same 40 buyer questions daily, Proofsource saw about one tracked name in five drop out of an answer overnight, and 47% of day-to-day changes reverse a day later (half of daily changes reverse). A single answer is a draw, not a verdict.
What should you measure for SEO and for GEO?
For SEO, keep the measures you have: impressions, clicks, average position and index coverage. Google counts appearances and clicks from AI Overviews and AI Mode in Search Console's Performance report under the Web search type, so that report already includes them, mixed in with your other Search traffic.
For GEO, measure the answers themselves, on questions buyers ask that do not name you:
- Mention rate per engine, with an interval, so a change can be told apart from noise.
- Who is named instead, and in what order.
- Which pages each engine cites, and whether they mention you.
- Whether answers to questions that do name you describe you correctly, tracked separately.
Read the two together. A page that gains clicks while the answers keep naming competitors is a GEO gap; answers that name you while clicks fall may simply be people reading the answer and not clicking.
Three GEO checks to run this week
Let the crawlers in
Check robots.txt and your CDN for each engine's search crawler, not only Googlebot.
Read the cited pages
On the questions you lose, open the pages the answers cite and see who they name.
Baseline the rate
Ask the same questions several times on each engine before changing anything.
Where does the term GEO come from?
From a 2023 research paper, GEO: Generative Engine Optimization, by Pranjal Aggarwal and colleagues. It described generative engines as systems that gather sources and summarize them with a language model, and reported that rewriting content can raise its visibility in those answers by up to 40% on the paper's own measures, with adding citations, quotations and statistics among the methods that worked best. AEO, answer engine optimization, is the name more common in marketing for the same work; see AEO vs SEO and the GEO definition.
How does Proofsource measure GEO?
It asks your buyer questions on ChatGPT, Perplexity, Claude and Google AI Overviews, on a schedule, and keeps every answer: the brands named, the order, the pages cited and the searches the engine ran. Each mention rate carries a 95% Wilson interval, and a change is flagged only once it is bigger than that interval. For each question you lose, it shows who won and the pages behind it, and drafts a fix held for your approval. The method is on the methodology page, and what a GEO tool does covers the category.
What people ask about GEO and SEO
Is GEO replacing SEO?
No. Generative engines that search the web read pages that are crawlable and indexed, and Google says the best practices for SEO remain relevant for its AI features. GEO adds a second test on top: whether the answer built from those pages names you, describes you correctly and cites you.
Can a page rank well on Google and still be left out of AI answers?
Yes. A ranking is a position for one URL; a generated answer is assembled from several sources, often third-party lists, reviews and comparisons, and some answers are written from what the model learned without any search. A page can hold its position while the answer names other brands.
What is GEO SEO?
Usually it means doing generative engine optimization alongside SEO: the same site work, measured in AI answers as well as in search results. The phrase is also used for geographic or local SEO, ranking in the results for a particular place, which is a different discipline.
Does GEO need different content from SEO?
Mostly the same pages, written so an engine can lift the answer: the answer in the first sentence under a heading that asks the question, facts in plain text in the HTML, and sources for claims. The bigger difference is off your site, on the third-party pages engines cite for your category.
How long does GEO take compared with SEO?
It depends on the engine. An engine that searches for each answer can reflect a changed page once it has been crawled again. An answer written from what a model learned changes only when the model is updated, and no vendor publishes that schedule. Measure the same questions over weeks and judge changes against the interval.
- Google Search Central: AI features and your website developers.google.com/search/docs/appearance/ai-features, page last updated Dec 10, 2025
- OpenAI: overview of OpenAI crawlers developers.openai.com/api/docs/bots, undated page
- Chen, Wang, Chen and Koudas (University of Toronto), Generative Engine Optimization: How to Dominate AI Search, arXiv:2509.08919 arxiv.org/abs/2509.08919, September 2025
- Aggarwal et al., GEO: Generative Engine Optimization (KDD 2024), arXiv:2311.09735 arxiv.org/abs/2311.09735, first posted Nov 16, 2023
Read on . Proofsource's own figures are linked to the post that reports each one, with its sample and its limits.
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