The Reframe

Answer engine optimization (AEO): what it is, how it differs from SEO, and how to start

By , The Reframe··9 min read
Cover: answer engine optimization explained, what AEO is and how to start

Answer engine optimization (AEO) is the practice of getting your brand mentioned, described accurately and cited in the answers that ChatGPT, Perplexity, Gemini and Google's AI features give. It builds on SEO rather than replacing it. This guide explains what changes, how answer engines pick sources, and a six-step way to start.

Key takeaways
  • AEO aims for mentions, accurate descriptions and citations inside AI answers, not just ranked links.
  • Google says optimizing for its AI features is still SEO, so strong SEO is the foundation, not a separate track.
  • Answer engines run several searches per question, so off-site mentions and comparison pages matter as much as your own rankings.
  • Start with a fixed prompt set and a baseline, fix your own pages, then earn mentions on the sources engines already cite.
  • Measure mention rate, share of voice, citations and accuracy monthly; clicks from AI apps are hard to attribute.

What answer engine optimization means

An answer engine is any system that replies to a question with a written answer instead of a list of links. ChatGPT, Perplexity, Gemini, Claude and Google's AI Overviews and AI Mode all work this way. Answer engine optimization (AEO) is the work of making sure those answers include your brand, describe it correctly and, where the engine shows sources, link to your pages or to pages that mention you.

HubSpot's AEO guide defines it as "the practice of improving how often and how accurately your business appears in AI-generated answers." That word "accurately" matters. For a B2B SaaS company, being named in the wrong category or for the wrong buyer can do as much damage as not being named at all.

The term is older than ChatGPT. It was first used for featured snippets and voice assistants, where the goal was to be the one answer read aloud. Today it mostly means getting into large language model answers, and it overlaps heavily with generative engine optimization (GEO) and "AI SEO." The labels differ; the work is largely the same. If you want the wider picture of what you're trying to win, start with our guide to what AI visibility is.

How much people search for AEO and its cousins

Search demand for these terms is a useful proxy for how fast the practice is spreading. Here is what the vocabulary looks like in Ahrefs Keywords Explorer (US, September 2026):

Bar chart of US monthly search volume: ai seo 8,500, generative engine optimization 7,200, answer engine optimization 5,000, geo seo 3,000, aeo vs seo 2,500, llm seo 1,600
US monthly search volume for AI search optimization terms. Source: Ahrefs Keywords Explorer, US, September 2026.

A few things stand out in the data:

AEO vs SEO: what actually changes

"AEO vs SEO" is searched about 2,500 times a month in the US, which tells you people suspect they need a whole new discipline. Mostly, they don't. Google's own guide to optimizing for generative AI features says it plainly: "From Google Search's perspective, optimizing for generative AI search is optimizing for the search experience, and thus still SEO."

That is true for Google's surfaces. It's less complete for ChatGPT and Perplexity, which have their own crawlers and draw on a broader mix of sources. What changes is less the technique and more the target, the unit of success and where you compete.

SEOAEO
What you winA ranked blue linkA mention, recommendation or cited source inside an answer
Typical queryShort keyword ("crm software")A full question with context ("best CRM for a 20-person agency that uses Gmail")
Main metricRankings, clicks, organic trafficMention rate, share of voice, citations, accuracy of description
Where you competeYour pages vs competitor pagesYour pages plus review sites, comparisons, forums, YouTube and press
Feedback loopSearch Console, rank trackersRepeated prompt testing and AI visibility tools; clicks are hard to attribute
FoundationCrawlable, indexable, clearly written pages that answer real questions. This part is shared.

If you want the fuller comparison, including how to split budget between the two, read GEO vs SEO. The short version: keep doing SEO well, then add the off-site and measurement work that SEO alone doesn't cover.

How answer engines choose what to say

You can't control a model's output, but you can understand the inputs. Answer engines build responses from two places.

What the model already knows

Models learn from large amounts of web text during training. If your category is discussed widely and your brand is consistently part of that discussion, the model is more likely to associate you with the category. This is slow to change and hard to measure directly.

What it retrieves at answer time

Most assistants now search the web before answering. Google describes a "query fan-out" technique in its AI features documentation: the system runs several related searches across subtopics and then assembles an answer. ChatGPT's search uses OpenAI's own crawler; per OpenAI's crawler documentation, "OAI-SearchBot is used to surface websites in search results in ChatGPT's search features," and sites that block it won't appear in those answers.

Fan-out is why ranking #1 for one keyword isn't enough. An Ahrefs study of 863,000 SERPs (March 2026) found that just 38% of AI Overview citations came from pages ranking in the top 10 for the query, down from 76% a year earlier. The rest came from pages ranking lower or not at all for that exact query.

Off-site signals matter too. In Ahrefs' analysis of 75,000 brands, branded web mentions had the strongest correlation with AI Overview visibility (0.664), well ahead of the number of backlinks (0.218). Correlation isn't causation, but the pattern matches what we see in practice: assistants repeat what the web says about you. Our guide to AI brand mentions covers how to earn more of them.

How to start with AEO: a six-step process

Here's the sequence we'd use for a B2B SaaS team starting from zero. It takes a few weeks of part-time effort to get the first loop done.

Six-step AEO process: 1 check access, 2 build a prompt set, 3 baseline, 4 fix your own pages, 5 earn third-party mentions, 6 re-measure monthly
The AEO loop. Steps 4 and 5 are where the work is; step 6 tells you whether it worked.
  1. Check that answer engines can reach you. Confirm your robots.txt allows Googlebot and OAI-SearchBot, and that key pages (homepage, product, pricing, comparison and docs pages) are indexed and render their main content as text. Blocking GPTBot only affects model training, not ChatGPT search, so decide on that separately.
  2. Build a prompt set from real buying questions. Write 25 to 50 prompts across four types: category ("best X for Y"), comparison ("X vs Y"), alternatives ("alternatives to competitor"), and problem ("how do I fix Z"). Pull wording from sales calls and support tickets, not just keyword tools.
  3. Record a baseline. Run the set in ChatGPT, Perplexity, Gemini and Google AI Mode. For each answer, log whether you're mentioned, who else is, which sources are cited and whether your description is accurate. Our AI visibility tracking guide covers cadence and reporting.
  4. Fix your own pages. Make it obvious what you are, who you serve and what you replace. Put a one-sentence definition of your product near the top of the homepage. Publish honest comparison and alternatives pages. Keep pricing and feature pages current, because stale facts get repeated.
  5. Earn mentions where answers come from. Your baseline shows the pages being cited. Get listed on the roundups, update your review profiles, contribute useful answers in the communities that keep coming up, and pitch data or expert commentary to the publications in your category.
  6. Re-measure every month. Rerun the same prompts and compare mention rate and share of voice against competitors. Keep the prompt set fixed so the trend means something.
TipSkip the shortcuts Google has already addressed. Its generative AI guide says Google Search doesn't use llms.txt files, that content doesn't need to be chopped into small chunks, and that manufactured mentions across the web provide little benefit. Spend that time on steps 4 and 5 instead.

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What AEO-friendly content looks like

There's no special format that guarantees a citation. But pages that get used in answers tend to share a few traits, and none of them hurt SEO.

How to tell if AEO is working

AEO is harder to measure than SEO, and it's worth being honest about that. PostHog's public AEO handbook lists the gaps well: there's no reliable prompt volume data, referrers from AI apps are often stripped so clicks show up as direct traffic, and the same prompt can give different answers on different runs.

That doesn't make it unmeasurable. It means you track a small set of metrics consistently:

For Google's surfaces, Search Console counts AI Overviews and AI Mode in the Performance report, and Google's guide points to a dedicated generative AI performance report as well. For ChatGPT and Perplexity you'll rely on prompt tracking, either by hand or with a tool. The LLM visibility guide goes deeper on setting those metrics up.

FAQ

What is answer engine optimization in simple terms?

It's the work of getting AI assistants to mention your brand, describe it correctly and cite your pages when people ask questions about your category. Think of it as SEO where the prize is a place in the written answer rather than a ranked link.

What is the difference between AEO and SEO?

SEO targets rankings and clicks on a results page. AEO targets mentions and citations inside AI-generated answers, which also draw on review sites, comparison articles and forums. The technical and content foundations are shared, and Google itself describes optimizing for its AI features as still SEO.

Is AEO the same as GEO?

In practice, mostly yes. Generative engine optimization (GEO) and AEO describe the same goal of appearing in AI answers; AEO is the older term and was first used for featured snippets and voice assistants. Pick whichever label your team uses and focus on the work.

How does answer engine optimization work?

Answer engines combine what the model learned in training with pages they retrieve at answer time, often by running several related searches. AEO improves your odds in both: clear, current pages that can be crawled and retrieved, plus consistent mentions of your brand across the sources engines trust.

Do I need an llms.txt file or special markup for AEO?

Not for Google. Its generative AI guide says Google Search doesn't use llms.txt files and that no special markup is required. OpenAI's crawler documentation doesn't mention it either, so treat it as optional at best and spend the time on clear pages and third-party mentions.

Sources

  1. Google Search Central: Optimizing your website for generative AI features on Google Search
  2. Google Search Central: AI features and your website
  3. OpenAI: Overview of OpenAI crawlers
  4. Ahrefs: Just 38% of AI Overview citations come from top 10 pages (March 2026)
  5. Ahrefs: An analysis of AI Overview brand visibility factors (75K brands studied)
  6. HubSpot: Answer engine optimization (AEO) guide
  7. PostHog handbook: Answer engine optimization (AEO)
HumaFounder of The Reframe. An electrical and aerospace engineer turned growth marketer with 10+ years of experience, including work with Fortune 500 tech and SaaS companies.