What is answer engine optimization (AEO)?
Answer engine optimization (AEO) is the work of getting a brand's content chosen as the source of an AI-generated answer. Where SEO aims for a ranking position on a list of links, AEO aims for an AI citation: a link or named mention inside the answer that Google AI Overviews, AI Mode, ChatGPT, Perplexity, Claude or Copilot writes for the user.
A simple example. Someone asks ChatGPT "what's the best accounting software for a three-person agency?" The answer recommends three products and links four sources. AEO is everything that decides whether your product is one of the three and your page is one of the four.
The term covers three overlapping goals:
- Being cited: your page is linked as a source.
- Being named: your brand appears in the answer text, linked or not.
- Being described correctly: what the answer says about you is true (see brand hallucination).
How does answer engine optimization work?
Answer engine optimization works on the way AI answer engines build answers: they run searches, retrieve pages, pick the passages that answer the question, and write a response that cites those pages. Each step is a place a page can win or drop out.
| Step | What the engine does | What AEO work addresses |
|---|---|---|
| Access | Its search crawler fetches the page | Crawlers allowed in robots.txt; content readable without JavaScript |
| Retrieval | It searches its index, often with many sub-queries | The page ranks for the question and its sub-questions |
| Selection | It picks passages that answer the question | Self-contained passages that answer first |
| Generation | It writes the answer and attaches sources | Clear, specific, verifiable facts worth quoting |
| Reputation | It weighs what other sites say about the brand | Mentions and coverage on sources the engine trusts |
Google describes the retrieval step for its own features directly. AI Overviews and AI Mode use query fan-out, issuing "multiple related searches across subtopics and data sources" to find supporting pages [6]. A page can be cited for a question it would never rank for directly, because it answered one of the hidden sub-queries.
Access is the step most often broken without anyone noticing. Each AI company runs a separate search crawler, and blocking it removes a site from that product's answers. OpenAI says sites that block OAI-SearchBot will not appear in ChatGPT search answers except as navigational links [9]. Vercel found the major AI crawlers from OpenAI, Anthropic, Meta, ByteDance and Perplexity do not execute JavaScript [10], so content that only appears after JavaScript runs cannot be cited from those crawls. The AI crawler entry covers which bot does what.
What is the difference between AEO and SEO?
AEO aims to be cited or named inside an AI-generated answer, while SEO aims to rank a page in a list of search results. The two share most of their foundations. Google says "there are no additional requirements to appear in AI Overviews or AI Mode, nor other special optimizations necessary," and that SEO best practices still apply [6].
| SEO | AEO | |
|---|---|---|
| Win condition | A high ranking position | A citation or mention in the answer |
| Unit | The page | The passage, and the brand |
| Where it shows | Search results pages | AI Overviews, AI Mode, ChatGPT, Perplexity and other assistants |
| Main metric | Rankings, clicks | Citations, citation share of voice, accuracy |
| Data from the platform | Clicks, impressions, queries (Search Console) | Impressions only for Google's AI features; none from most others [8] |
| Off-site factor | Backlinks | Backlinks plus brand mentions on sources AI engines trust |
Search Insider's data shows how closely the two are tied on Google. When keywords were edited, AI Overview citations "moved with the organic results rather than independently" [12]. Ranking well is still the most reliable route into Google's AI answers.
Is AEO the same as GEO?
AEO and GEO are two names for nearly the same practice, and most people use them interchangeably. Generative engine optimization (GEO) comes from a November 2023 research paper about optimizing content for AI systems that generate answers [2]. AEO is older and was coined for direct-answer features before generative AI search existed [1].
Where a difference is drawn, it is one of emphasis:
- AEO stresses being the answer: chosen, quoted and cited for a question.
- GEO stresses visibility inside generated text, the outcome the GEO paper set out to measure [2].
- LLMO (LLM optimization) and "AI search optimization" are further labels for the same territory.
Search Insider uses AEO as the umbrella term because it describes the goal rather than the technology, and the goal has stayed the same while the technology changed.
When did answer engine optimization start?
Answer engine optimization started as a term around 2017 and 2018, when Google's featured snippets and voice assistants began giving a single direct answer instead of a list of links [1]. Its meaning shifted from featured snippets to AI-generated answers after 2023, as Google, OpenAI and others launched AI search products.
2017 to 2018: the term appears
Jason Barnard, founder of Kalicube, says he coined "answer engine optimization" in 2017, in response to Google surfacing direct answers in place of normal results [1]. The earliest independent write-up his company cites is a Search Engine Watch article by Rebecca Sentance, published February 7, 2018, which credited him with the idea [1]. At this stage AEO meant featured snippets, answer boxes and voice search.
2023: generative engine optimization
On November 16, 2023, researchers led by Pranjal Aggarwal published "GEO: Generative Engine Optimization," later presented at KDD 2024. The paper reported that optimization could raise a source's visibility in generative engine responses by up to 40%, and that what worked "varies across domains" [2]. It gave the field its first benchmark and a second name.
2024: AI Overviews
Google launched AI Overviews in the US on May 14, 2024, after testing the feature as the Search Generative Experience from May 2023, and expanded it to more than 100 countries in October 2024 [3]. AI-written answers with source links became part of ordinary Google Search, and AEO shifted from featured snippets to AI citations.
2025: AI Mode
On March 5, 2025, Google announced AI Mode, a separate conversational mode for complex questions [4]. It opened to all US users on May 20, 2025 [13]. The same announcement in March said AI Overviews reached more than a billion users [4].
2026: Google measures AI visibility
On May 19, 2026, Google said AI Mode had passed one billion monthly users [5]. On June 3, 2026, it announced Search Console reports of impressions in its AI features and a setting that lets sites leave those features, both rolled out worldwide by August 31, 2026 [7][8]. For the first time, AEO had first-party data from the largest answer engine, though only impressions.
What actually works in answer engine optimization?
What actually works in answer engine optimization is mostly what works in SEO, applied at the level of passages and brands: rank for the questions, answer them clearly, and be described accurately across the web. The evidence for specific tactics is thinner than most AEO advice suggests.
What has evidence or first-party support:
- Ranking for the question and its sub-questions. Google's AI features retrieve from its search index via query fan-out [6], and Search Insider found AI Overview citations follow organic results [12].
- Crawler access. Blocking an AI search crawler removes a site from that engine's answers [9].
- HTML the crawler can read. Most AI crawlers do not run JavaScript [10].
- Content edits tested in research. The GEO paper tested a set of content changes and reported visibility gains of up to 40%, with results that varied by domain [2]. Its findings come from a research benchmark, not from live engines today.
What the evidence does not support:
- Surface edits to titles. Search Insider tested 17,240 ranking pages across 1,000 searches. A year in the title showed no measurable AI Overview citation advantage once pages of the same age were compared, and pages with an expired year were cited least of all [11].
- Special AI-only optimizations for Google. Google states there are no additional requirements or special optimizations for appearing in AI Overviews or AI Mode [6].
How do you measure AEO?
You measure AEO by tracking how often AI answers cite you, how that compares with competitors, and whether what they say about you is correct. Four measures cover most needs:
- AI citations: how often your pages are linked as sources, on a fixed set of questions, per engine.
- Citation share of voice: your share of all citations in that answer set.
- Brand mentions: how often your brand is named, linked or not (see share of model).
- Accuracy: the share of factual claims about your brand that are correct.
Google Search Console adds impressions in AI Overviews, AI Mode and Discover AI features, by page, country and date, but no clicks [8]. Search Insider is not aware of any other major AI company giving site owners equivalent data. Everything beyond Google's impressions comes from sampling answers with your own prompts or a tracking tool, which is why the prompt set and method need to stay fixed between reports.
Does AEO replace SEO?
No. AEO does not replace SEO, because the largest answer engines retrieve their sources from search indexes and favor pages that already rank. Google states its AI features need no optimization beyond normal SEO [6], and Search Insider's data shows Google's AI citations moving with organic rankings [12].
What AEO adds is a different scoreboard and a few extra checks: separate crawler access per AI company, passage-level writing, brand accuracy across third-party sources, and citation tracking where Search Console stops. A team doing SEO well is most of the way to doing AEO.
What is not known about AEO?
No AI company publishes how it chooses which sources to cite, and no answer engine publishes click-through rates for citations. Studies of AEO measure correlation on a sample of questions at one point in time; they show what tends to be cited, not why. Google itself reports only impressions [8]. Claims of a guaranteed AEO ranking factor, a fixed citation formula or a specific AEO click-through rate go beyond any published evidence.
When should you invest in answer engine optimization?
Invest in answer engine optimization when customers research your category by asking questions, comparing options or seeking recommendations, because those are the searches AI answers now cover first. Start with the low-cost checks: AI search crawlers allowed, key facts in plain HTML, and a brand audit of what AI tools currently say about you. Then track citations on a fixed question set, and keep the SEO work that feeds both.