AEO vs SEO: what is the difference?

Search engine optimization (SEO) is the work of getting a website's pages ranked and clicked in search results. Answer engine optimization (AEO) is the work of getting a company named, cited, and described correctly in answers written by AI systems such as ChatGPT and Google's AI Overviews. AEO rests on SEO, because answer engines retrieve their sources from search indexes. It differs in what counts as success, which pages earn it, and how it is measured.

So the question of SEO vs AEO is not a choice between two programs. Google says that optimizing for generative AI search "is optimizing for the search experience, and thus still SEO" (opens in a new tab). This page sets out what the two share, where they differ, and which to work on first, with the evidence for each point. It is part of AEO HQ's complete guide to the practice. The same question under the research label GEO is covered in GEO vs SEO, which lists where each AI system retrieves its sources. Sources were checked on September 27, 2026.

Definitions

• Search engine optimization (SEO). Bing's guidelines describe SEO as work that "improves the technical quality, clarity, and accessibility of websites, helping Bing discover, understand, and evaluate content" (opens in a new tab). Google describes search in three stages: crawling, indexing, and serving search results, and notes that not all pages make it through each stage (opens in a new tab). "Traditional SEO" usually means work aimed at the ranked list of links.
• Answer engine optimization (AEO). Google says AEO and GEO "are both terms you may see used to describe work specifically focused on improving visibility in AI search experiences" (opens in a new tab). A 2026 field study calls AEO "a practice analogous to search engine optimization" (opens in a new tab). AEO vs GEO compares AEO with the other labels in use.
• Answer engine. A system that answers a question in its own words and names or links its sources, such as ChatGPT, Perplexity, Claude, Microsoft Copilot, and Google's AI Overviews and AI Mode.
• Citation and mention. A citation is a link to a source shown with an answer. A mention is the company's name in the answer, with or without a link.
• Grounding. Basing an answer on pages retrieved from a search index, rather than on the model's memory alone.

Comparison table

Where AEO and SEO overlap

Answer engines search before they answer, and they search indexes that crawlers build. Google says its generative AI features are "rooted in our core Search ranking and quality systems" (opens in a new tab), and that to appear in AI Overviews or AI Mode a page must be indexed and eligible to be shown with a snippet (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 other assistants document the same dependence: Microsoft Copilot sends its queries to the Bing search service (opens in a new tab), ChatGPT search relies on OpenAI's search crawler and on partner search providers that include Microsoft (opens in a new tab), Anthropic lists Brave Search and TurboPuffer as its web search subprocessors (opens in a new tab), and Perplexity's crawler is designed to surface and link websites in Perplexity's search results (opens in a new tab). A page that search cannot reach cannot be cited: OpenAI says sites that opt out of its search crawler "will not be shown in ChatGPT search answers" (opens in a new tab).

Rank also carries over. In a NeurIPS 2025 benchmark, traditional SEO strategies, which improve a page's position among the sources the model reads, were significantly more effective than rewriting the page (opens in a new tab). In 252,000 controlled trials across six models, topical relevance and list position were the biggest drivers of which source was cited first (opens in a new tab) (peer-reviewed; laboratory; the authors work for a marketing software company).

The shared foundation is therefore crawl access, indexing, fast and readable pages, relevance to the query, and pages that rank. Work on these serves both.

Where AEO differs from SEO

The unit is an answer to a question

SEO targets a query and a results page. AEO targets a question and the answer written for it. AI answers appear most often for questions: in Pew's March 2025 browsing data, 60% of searches starting with a question word produced an AI summary (opens in a new tab), and in a March–April 2026 crawl of trending queries, AI Overviews appeared for 13.7% of queries overall and 64.7% of question-form queries (opens in a new tab) (preprint). The engines then turn a question into their own searches. OpenAI says ChatGPT search "typically rewrites your query into one or more targeted queries" (opens in a new tab), and Google says AI Overviews and AI Mode may use query fan-out, "issuing multiple related searches across subtopics and data sources" (opens in a new tab).

Buyers write long, specific prompts. In a March–April 2026 survey of 519 U.S. B2B professionals who use AI at work, 61% said they describe their specific use case when researching vendors with AI, and 56% ask for direct vendor comparisons (opens in a new tab) (vendor survey). Pages that answer a use-case question or a comparison in plain words fit that behavior. How to write content for answer engines covers the method.

Being named counts, not only being linked

In SEO, success is a click on your link. In AEO, an answer can recommend a company without linking to it. In an audit of AI product recommendations published in September 2026, ChatGPT expressed a first-person product preference in 79% of the responses that recommended products (opens in a new tab) (preprint). Buyers act on those names: in the Semrush survey, 71% said they visit a vendor's website after an AI names the vendor (opens in a new tab). In a March 2026 survey of 1,076 B2B software buyers, 51% said they now start their research with an AI chatbot more often than with Google, up from 29% eleven months earlier (opens in a new tab) (survey by a software review platform).

Other sites do more of the work

A ranking page is usually your own. The sources behind an AI answer usually are not. In API tests with ranking-style prompts, ChatGPT drew 93.5% to 95.1% of its cited sources from earned media such as reviews and editorial coverage (opens in a new tab) (preprint; mid-2025). In a panel of 102 brands on five AI engines (March–May 2026), only 2.9% of citations pointed at the brand's own domain (opens in a new tab) (preprint; the author co-founded the tracking platform studied). Across 75,000 brands, mentions of a brand on the web tracked AI visibility far more closely than backlinks did (opens in a new tab), although a correlation does not show that mentions cause visibility. Google cautions that seeking inauthentic "mentions" across the web "isn't as helpful as it might seem" (opens in a new tab), so the mentions have to be earned. The guide to brand mentions covers how.

Specific facts carry more weight, and buyers check them

An answer engine compares sources passage by passage. In the six-model trials above, an explicit price and a recent date raised the odds of being cited first in all six models, while formatting alone had no consistent effect (opens in a new tab). Buyers then check the facts. In a January 2026 survey of 1,862 technology buyers, 94% of those who used AI said they fact-check its responses at least some of the time (opens in a new tab), and in the Semrush survey, 27% said AI vendor recommendations don't reflect real pricing or contract structures (opens in a new tab). A page that states price, scope, and terms plainly can be both cited and confirmed.

Being cited is also not the same as being described correctly. In March and April 2026, 11.0% of 98,020 atomic claims in Google AI Overviews were not supported by the pages they cited (opens in a new tab) (preprint). AEO therefore includes checking what answers say about you, which SEO does not measure.

Answers vary, so AEO is measured as a rate

A search ranking can be checked with one query. An AI answer cannot. When 600 volunteers ran the same prompts 2,961 times, ChatGPT and Google's AI gave the same list of brands in less than 1 of 100 runs, and Claude only slightly more often (opens in a new tab) (November–December 2025; industry study; a co-investigator works for a tracking vendor). Results also depend on the interface: the API and the consumer app of the same assistant shared only 12.0% (ChatGPT) and 14.8% (Gemini) of cited domains (opens in a new tab) (preprint). AEO visibility is reported as the share of repeated runs that mention or cite the company, per engine. How to measure AI visibility sets out the method.

The first-party reports differ too. Beyond the generative AI report, Google says traffic from AI Overviews and AI Mode is included in the overall "Web" search type of Search Console's Performance report (opens in a new tab), not shown separately. Bing's AI Performance report counts citations and grounding queries. GA4's AI Assistant channel excludes Google's AI Overviews and AI Mode, which it counts as Organic Search (opens in a new tab).

Clicks are fewer, and AI referrals undercount influence

Pew found that users clicked a link inside the AI summary itself on 1% of visits (opens in a new tab). Referral traffic from assistants is small and converts unevenly: across 973 e-commerce sites, ChatGPT referrals converted better than paid social but worse than every other traditional channel (opens in a new tab) (peer-reviewed; last-click data from August 2024 to July 2025). Referrals also miss visits: traffic referred by Claude's native app carries no Referer header (opens in a new tab), and in one agency's records, 189 of 213 leads who answered "how did you hear about us" named an AI tool, but first-touch attribution credited AI with only 28 of them (opens in a new tab) (single firm; the agency sells AEO services). AEO needs a self-reported source question as well as referral data.

Some SEO habits do not carry over

• Keyword repetition. The authors of the original GEO paper found that keyword stuffing, while "widely used for Search Engine Optimization," (opens in a new tab) offered "little to no improvement on generative engine's responses" (opens in a new tab).
• Rewriting pages to suit the engine. A NeurIPS 2025 benchmark found statistically significant ranking gains in only 3 of 54 cases, and adding statistics lowered rankings in 19 of 24 settings (opens in a new tab).
• Tracking a position. Brand lists in AI answers change from run to run, and ordering is less stable still: SparkToro estimated it takes about 1,000 runs before two lists appear in the same order (opens in a new tab). A rank in an AI answer is not a stable number.

When to use each

Most B2B sites need both. The question is which gap to close first. These are AEO HQ's recommendations, based on the evidence above.

AEO HQ runs the two as one program and calls it AI search optimization: SEO plus third-party corroboration, specific facts, and measurement across repeated runs.

Is AEO replacing SEO?

The evidence does not support that. Google says its AI features are built on its core search ranking and quality systems (opens in a new tab), Bing says Copilot relies on the same crawling, indexing, and ranking foundation as traditional search (opens in a new tab), and the other assistants retrieve from search indexes too. What has changed is where some buyers start and how often they click. G2 found that 51% of B2B software buyers now start their research with an AI chatbot more often than with Google (opens in a new tab), and Pew found that users clicked a traditional result on 8% of visits with an AI summary, against 15% without one (opens in a new tab). SEO keeps a page retrievable and ranked; AEO adds the work that decides whether an answer names the company and gets its facts right.

Common mistakes

1. Treating AEO as a separate channel that does not need indexing. Answer engines retrieve from indexes, and a site that blocks OpenAI's search crawler is not shown in ChatGPT search answers (opens in a new tab).
2. Reporting an "AI ranking". Answers repeat less than once in 100 runs (opens in a new tab). Report the share of runs that mention the company, per engine, instead.
3. Working only on your own site. Most cited sources are earned media (opens in a new tab). Plan for coverage, reviews, and comparisons on other sites.
4. Hiding prices and scope behind a form. Stated prices raised citation odds (opens in a new tab), and 27% of surveyed B2B professionals said AI vendor recommendations don't reflect real pricing (opens in a new tab). Publish what you can.
5. Judging AEO by referral traffic alone. Referrals are small (opens in a new tab) and undercount AI-sourced leads (opens in a new tab). Add a "how did you hear about us" question and first-party AI reports.
6. Rewriting pages to sound "AI-friendly". Rewriting rarely helped and often hurt rank (opens in a new tab), and Google says site owners don't need to "write in a specific way just for generative AI search" (opens in a new tab).
7. Publishing a page for every phrasing of a question. Google treats this as scaled content abuse when the aim is to manipulate rankings or AI responses (opens in a new tab).
8. Buying a guarantee. Google's guidance on third-party services names "AEO" and "GEO" tools, tells site owners to be wary of claims that a service is approved by Google, and says third-party tools "can't guarantee performance" (opens in a new tab).

Next steps

AEO HQ's AEO Audit ($2,500) covers both sides in one review: a technical SEO audit, a content and topical coverage audit, and an AI visibility audit across ChatGPT, Perplexity, Gemini, and AI Overviews. Packages run from a $499 automated audit to $8,995 for an audit, a plan, and technical implementation. See what each AEO service includes.