AEO vs SEO vs GEO: what's the difference?

The short version

SEO, AEO and GEO describe overlapping work. SEO aims for ranked results. AEO and GEO aim for your content to be used and cited when an AI search product writes an answer. In practice, AEO and GEO are two names for the same goal, and both sit on top of SEO.

The rest of this post explains each row and the parts that genuinely differ.

Try it as you read: take the free first lesson and see how answer engines choose their sources.

What is SEO, in this comparison?

SEO is the practice you already know: making pages crawlable, indexable, relevant and trustworthy so they rank in search results. The reason it matters here is that AI search is built on the same index.

Google's AI features documentation says that to be a supporting link in AI Overviews or AI Mode, "a page must be indexed and eligible to be shown in Google Search with a snippet." It adds that "The best practices for SEO remain relevant for AI features in Google Search." If a page fails at SEO, it is usually out of the running for AI answers on Google too.

What is AEO?

AEO, answer engine optimization, is the practice of getting your content used and cited by answer engines: products that read pages for the user and write a response with links to sources. Google's AI Overviews and AI Mode, Copilot Search in Bing, ChatGPT search, Perplexity and Claude with web search all work this way.

AEO has no official definition and no standards body behind it. It's a practitioner term. We use it at Learn AEO because "answer" describes what the user gets, and it applies across every engine. For a fuller explanation, see What is answer engine optimization (AEO)?.

What is GEO?

GEO, generative engine optimization, has a clearer origin. It comes from the paper "GEO: Generative Engine Optimization" by Pranjal Aggarwal, Vishvak Murahari and colleagues, first posted to arXiv in November 2023 and accepted to KDD 2024.

The paper names the systems it studies: "We dub these systems generative engines (GE) because they search for information and generate multi-modal responses" from multiple sources. It describes GEO as "the first novel paradigm to aid content creators in improving their content visibility in generative engine responses."

What the paper found:

• •A benchmark. The authors built GEO-bench, "a benchmark consisting of 10000 queries from diverse domains and sources."
• •Content changes can help. The abstract reports that "GEO can boost visibility by up to 40% in generative engine responses." The methods tested included adding quotations, statistics and citations to sources.
• •One real engine. On Perplexity.ai, "Quotation Addition performs best in Position-Adjusted Word Count with a 22% improvement over the baseline."
• •Keyword stuffing doesn't carry over. For that classic tactic, the authors report "such methods offer little to no improvement."
• •Smaller sites gained more. The paper says "lower-ranked websites, which typically struggle for visibility, benefit significantly more from GEO."

Keep the scope in mind. These results use the paper's own benchmark and visibility metrics, mostly with an engine the authors built on gpt-3.5-turbo, plus one test on Perplexity.ai. They are evidence that clear, well-supported content gets used more in generated answers. They are not a forecast for any particular engine today.

Since the paper, GEO has spread beyond research. Bing's February 2026 post introducing the AI Performance report in Bing Webmaster Tools calls it "an early step toward Generative Engine Optimization (GEO) tooling."

Where do LLMO and AIO fit?

They're more labels for the same territory. LLMO (large language model optimization) and AIO have no official definitions either. Conductor's glossary calls LLMO "essentially synonymous with Generative Engine Optimization (GEO)." Microsoft treats GEO, AIO and SEO as interchangeable labels. Its October 2025 post on AI search answers says: "Whether you call it GEO, AIO, or SEO, one thing hasn’t changed: visibility is everything."

When you read a proposal, an agency pitch or a job ad that uses any of these terms, ask what work it actually describes. The label tells you less than the task list.

Do AEO and GEO need different tactics from SEO?

Mostly no. The engines say the foundation is the same:

• •Google: "There are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary."
• •Microsoft Advertising: "traditional SEO fundamentals still matter," naming crawlability, metadata, internal linking and backlinks.
• •Google's May 2025 guidance on AI search asks for "unique, non-commodity content that visitors from Search and your own readers will find helpful."

None of this is new to an SEO. Here's how the shared work splits:

What actually differs?

Four things are genuinely new, whichever acronym you use.

1. You compete for a citation, not a position. An answer links to the sources it relied on, not to every page it found. OpenAI notes that "The number of sources is often greater than the number of citations," so a page can be read and still not get the link.

2. Passages are the unit. Microsoft's post says "AI assistants don't read a page top to bottom like a person would" and recommends "Sentences that make sense even when pulled out of context." Google says its AI Mode uses a "query fan-out technique, breaking down your question into subtopics," so a single page may be found through a search you never targeted. See query fan-out and passage ranking.

3. More crawlers matter. Each engine has its own bots with their own rules. OpenAI says "Sites that are opted out of OAI-SearchBot will not be shown in ChatGPT search answers." Perplexity says PerplexityBot "is designed to surface and link websites in search results on Perplexity." A robots.txt rule written years ago can quietly remove you from an engine. Our AI crawler checker shows what your file allows.

4. Measurement is new. Bing's AI Performance report counts "Total Citations" and shows a sample of "Grounding queries." Google says traffic from its AI features is "included in the overall search traffic in Search Console," under the Web search type of the Performance report. For engines without a report, check the answers to your key questions directly.

Which one should you learn?

Learn the work, not the acronym. If you already know SEO, you have the base. The additions are concrete: crawler access for AI search bots, writing citable passages, keeping structured data honest, building accurate mentions on other sites, and measuring citations alongside rankings.

What you shouldn't do is chase tricks sold under any of these names. Google's spam policies count attempts to manipulate "generative AI responses in Google Search" as spam, and list cloaking, hidden text and keyword stuffing among the practices they cover. The GEO paper found keyword stuffing offered "little to no improvement" anyway.

Call it AEO, GEO or plain SEO. The job is the same: be the clearest, most trustworthy source for the questions your buyers ask, and make sure every engine can reach it.