AEO vs GEO (and AIO, LLMO): are they the same thing?

Mostly, yes. Answer engine optimization (AEO), generative engine optimization (GEO), AI optimization (AIO), and large language model optimization (LLMO) are overlapping labels for one practice: getting a brand or page retrieved, cited, and described accurately in AI-generated answers. Google describes AEO and GEO as terms for work "specifically focused on improving visibility in AI search experiences" (opens in a new tab), and G2 lists AEO software as "also known as generative engine optimization (GEO)" (opens in a new tab). The labels differ in origin and emphasis, not in method.

This page explains what each label means, where it comes from, how platforms, directories, researchers, and searchers use it, and where the emphasis differs. It is part of the complete guide to the practice.

Definitions

• Answer engine. An AI system that replies to a question with a written answer instead of a list of links, such as Google's AI Overviews, ChatGPT, or Perplexity.
• Generative engine. The GEO paper's term for a system that typically answers by "synthesizing information from multiple sources and summarizing them using LLMs" (opens in a new tab).
• LLM. A large language model, the kind of model that writes these answers.
• SEO. Search engine optimization: work that helps search engines find, index, and rank a site's pages.
• Retrieval. Picking pages from a search index to use as sources for an answer.
• Grounding. Basing an answer on retrieved pages.
• Parametric knowledge. What a model learned in training and can state without retrieving anything.

Comparison table

The last column is AEO HQ's reading of how each label is used. It is not a documented definition.

How the labels are used

Platforms

Google's guidance explains that "AEO" stands for "answer engine optimization" and "GEO" for "generative engine optimization", and that they "are both terms you may see used to describe work specifically focused on improving visibility in AI search experiences" (opens in a new tab). For its own part, Google says that optimizing for generative AI search "is optimizing for the search experience, and thus still SEO" (opens in a new tab). Its advice on third-party services refers to "AI experiences (sometimes called AEO for 'answer engine optimization' or GEO for 'generative engine optimization')" (opens in a new tab).

Bing's webmaster guidelines use only GEO, which they say "focuses on content eligibility for grounding and reference in AI responses" (opens in a new tab).

Directories

G2, a software review site, describes its category as "Answer engine optimization (AEO) software, also known as generative engine optimization (GEO)", and listed 642 products in it on 27 September 2026 (opens in a new tab).

Clutch, an agency directory, lists firms under "Generative Engine Optimization (GEO)" and says GEO is "also known as answer engine optimization (AEO) or LLM optimization"; it listed more than 1,500 firms on 27 September 2026 (opens in a new tab).

Research

Most research uses GEO. A 2026 review grouped 45 studies under that name and noted that "terminology, metrics, and evidence standards remain heterogeneous" (opens in a new tab) (preprint). Some studies use other names for the same problem. A 2025 benchmark calls it "Conversational Search Engine Optimization (C-SEO)" (opens in a new tab), and a 2026 field study calls it "Answer Engine Optimization (AEO)", "a practice analogous to search engine optimization" (opens in a new tab).

Search

Ahrefs estimates pulled by AEO HQ on 27 September 2026 show how often people in the United States search for each label:

These are modeled estimates. Use them to compare terms, not as exact counts. The bare acronym "aeo" also collides with the retailer American Eagle Outfitters: in the same data, "aeo stock" had about 25,000 searches a month.

AIO and LLMO

AIO has two meanings. As a name for this work, it is read as "AI optimization", and it appears in searches such as "answer engine optimization aio" (see the table above). The same letters are a common short form of Google's AI Overviews. For example, Seer Interactive's click-through studies refer to "Google's AI Overviews (AIOs)" (opens in a new tab). Check which meaning a writer intends.

LLMO is rare as an acronym. The only query in the data that used it, "aeo vs geo vs llmo", returned an estimate of 0. The spelled-out forms are more common: "LLM optimization" appears in Clutch's description above, and "llm seo" draws about 1,600 searches a month.

Same practice, same evidence

Whatever the label, the work rests on the same mechanism and the same studies.

• The same gate. Google's AI Overviews and AI Mode can only show pages that are indexed and eligible to appear with a snippet; no special optimization is required (opens in a new tab). Bing says "Bing and Copilot search experiences rely on the same core crawling, indexing, and ranking foundation as traditional search" (opens in a new tab). The label on the work does not change this.
• The same tests. In the original GEO experiments, adding quotations raised a source's share of the generated answer by about 41% and adding statistics by about 31%, in a simulated engine where the page was already retrieved (opens in a new tab). When a 2025 benchmark re-tested such methods, it found statistically significant gains for conversational-SEO methods in 3 of 54 cases, and adding statistics lowered rank in 19 of 24 (opens in a new tab). Those results apply to advice sold under any of the four labels.
• The same ideas under the AEO name. The only controlled field study in AEO HQ's research review uses the AEO label. It changed one website's pages with question-form titles, standalone summaries of two to three sentences, consolidated duplicate URLs, and new pages for addresses that AI crawlers had requested but that did not exist. It estimated a 1.82-fold rise in ChatGPT referrals relative to unchanged pages on the same site (95% confidence interval 1.31 to 2.54) (opens in a new tab). A placebo test gave p = 0.16, so the authors call the effect "suggestive, not conclusive" (opens in a new tab) (preprint; the authors work for the company whose site was studied).

Where the emphasis differs, and when to use each

The differences below are AEO HQ's reading of how the labels are used, not documented definitions.

• AEO points at the answer. It fits discussions of question-led pages, and of being recommended when a buyer asks an assistant which vendor to use.
• GEO points at the generative system and carries the research. Most studies and Bing's guidelines use it.
• AIO is too ambiguous to use on its own.
• LLMO points at the model. That matters because not every answer is retrieved. A 2025 study found substantial variation among engines in their reliance on internal versus external knowledge (opens in a new tab), and in its tests GPT-4o with a search tool retrieved a median of zero links and answered static questions from its own knowledge (opens in a new tab) (preprint). Those answers come from the model's parametric knowledge, which work on retrieval does not change directly.

Recommendations:

1. Use the label your readers use, and define it at first use. AEO and GEO both have large search demand (see the table above), and both acronyms can mean other things.
2. Write AIO out in full. Say "AI optimization" or "AI Overviews", whichever you mean.
3. Use GEO when you look for or cite research. It is the term most studies use.
4. Judge services by scope and evidence, not by label. Google lists "promising improvements for AI experiences and search formats (also known as 'AEO' or 'GEO' tools)" (opens in a new tab) among the third-party services whose claims buyers should check, and says third-party tools "can't guarantee performance" (opens in a new tab).
5. Keep SEO in the plan under any label. AEO HQ uses AI search optimization as its umbrella term: SEO plus corroboration, specific facts, and measurement. How each label relates to SEO is set out in the AEO vs SEO comparison and the GEO vs SEO comparison.

Common mistakes

1. Paying twice for one practice. Google, G2, and Clutch all describe AEO and GEO as names for the same work, as quoted above. Buying "AEO" and "GEO" as separate services for the same pages pays twice for one job.
2. Treating a new label as new evidence. Renaming the practice does not change what the studies found. The "up to 40%" figure comes from a simulated setup in the original GEO paper (opens in a new tab), and a 2026 review calls the paper's widely cited gains "valid within its experimental setting but conditional on a source already being present in a fixed context" (opens in a new tab) (preprint).
3. Reading "AIO" without checking its meaning. It can mean AI optimization or Google's AI Overviews.
4. Assuming any label replaces SEO. Google's AI features can only show pages that are indexed and eligible to appear with a snippet (opens in a new tab), whatever the work is called.
5. Believing a label brings a guarantee. Bing states that "GEO does not guarantee grounding or citations in AI experiences" (opens in a new tab).

Next steps

AEO HQ sells this work under the AEO name, at fixed, published prices from a $499 automated audit to $8,995 for an audit, a plan, and technical implementation. The services page lists what each package includes.