The short answer
SEO (Search Engine Optimization) optimizes your website to rank as a link in traditional search results. AEO (Answer Engine Optimization) optimizes it to be cited in AI-generated answers from ChatGPT, Perplexity, and similar systems. GEO (Generative Engine Optimization) means the same thing as AEO, with an emphasis on generative surfaces like Google AI Overviews and Gemini.
In practice you are dealing with two disciplines, not three: traditional SEO as the foundation, and AEO/GEO as the layer that determines whether AI systems cite your brand. Neither replaces the other — but the visibility, and the traffic, is shifting toward the AI layer.
The three terms, defined
SEO — Search Engine Optimization
The established practice of improving rankings in search engines through content, backlinks, and technical health. Success is measured in positions and organic clicks. Full SEO guide →
AEO — Answer Engine Optimization
Optimizing websites and content so answer engines — ChatGPT, Perplexity, Claude — cite or recommend your brand when users ask relevant questions. Success is measured in citation frequency. Full AEO guide →
GEO — Generative Engine Optimization
The same discipline as AEO, framed around generative AI surfaces: Google AI Overviews, Gemini, and Microsoft Copilot. The strategies and tooling are identical. Full GEO guide →
SEO vs AEO vs GEO at a glance
| SEO | AEO | GEO | |
|---|---|---|---|
| Goal | Rank as a link in search results | Be cited in AI-generated answers | Be visible in generative AI results |
| Where results appear | Google/Bing blue links | ChatGPT, Perplexity, Claude | Google AI Overviews, Gemini, Copilot |
| Primary signals | Keywords, backlinks, technical health | Answer-ready content, schema, llms.txt, citations | Same as AEO |
| Measured by | Rankings, organic traffic | Citation frequency, AI visibility score | Citation frequency, AI visibility score |
| Maturity | 25+ years, established playbook | Emerging, land-grab phase | Emerging, land-grab phase |
The AEO and GEO columns are deliberately near-identical. The split between the two terms is historical, not technical: "GEO" comes from a 2023 academic paper on generative engines, while "AEO" grew out of the answer-engine framing used by tool vendors and agencies. The market currently uses both.
GEO vs SEO: what actually changes
GEO is not a rejection of SEO — it is what SEO turns into when the results page becomes an answer. Generative engines still crawl the web, still weigh authority, and still favor well-structured content. A site with weak SEO fundamentals will not perform in AI answers either.
What changes is the optimization target and the work it demands:
- From rankings to citations: There is no position 1–10 in a generated answer. Either the model cites you, or it cites a competitor. Visibility becomes binary per query.
- From keywords to questions: Generative engines respond to full questions. Content structured as direct answers — definitions, FAQs, comparison tables — gets retrieved and quoted more often.
- From crawl budget to crawler access: GPTBot, ClaudeBot, PerplexityBot, and Google-Extended must be explicitly permitted in robots.txt, and llms.txt gives models a machine-readable summary of your site.
- From backlinks to entity trust: AI models build a picture of your brand from directories, reviews, and third-party mentions. Consistency across those sources matters as much as raw link volume.
AEO vs GEO: two names, one discipline
If you optimize a site for ChatGPT citations, you have also optimized it for Google AI Overviews. The signals — schema markup, answer-ready content, crawler access, third-party authority — are the same. That is why AEO and GEO are best treated as synonyms rather than separate service lines.
The practical difference is audience language. Clients who noticed their traffic dropping after AI Overviews rolled out tend to search for GEO; clients asked by their board "why doesn't ChatGPT mention us?" tend to search for AEO. Use whichever term your audience uses — the audit behind it is identical.
Do you need SEO, AEO, and GEO?
You need both layers: SEO as the foundation, AEO/GEO as the growth layer. For agencies, this is the commercially important point — existing SEO retainers already cover the foundation, and AEO/GEO is the natural expansion service clients are starting to ask for by name.
The starting point is knowing where a site stands today. Kaistone's AI Audit Engine scores a site's AI visibility across ChatGPT, Perplexity, Google AI Overviews, Gemini, and Claude, and the Recommendations Engine turns the findings into a prioritized roadmap you can hand to a client.
Frequently asked questions
What is the difference between AEO and GEO?
AEO (Answer Engine Optimization) and GEO (Generative Engine Optimization) describe the same discipline — optimizing to appear in AI-generated answers — from two angles. 'AEO' emphasizes answer engines like ChatGPT and Perplexity that respond to direct questions. 'GEO' emphasizes generative AI surfaces like Google AI Overviews and Gemini. The optimization work — structured data, answer-ready content, authority signals, llms.txt — is identical, so most practitioners use the terms interchangeably.
What is the difference between SEO and AEO?
SEO optimizes a website to rank as a link in traditional search results. AEO optimizes a website to be cited inside AI-generated answers. SEO success is measured in rankings and organic clicks; AEO success is measured in citation frequency across platforms like ChatGPT, Perplexity, and Google AI Overviews. AEO builds on SEO fundamentals but adds AI crawler access, llms.txt, answer-formatted content, and brand entity consistency.
Is GEO replacing SEO?
No. GEO is a layer on top of SEO, not a replacement. AI systems still rely heavily on the same signals traditional search uses — crawlable content, authority, structured data. A site with weak SEO fundamentals will underperform in generative engines too. What changes is where the visibility appears: increasingly inside AI answers rather than as ranked links.
Do I need separate strategies for SEO, AEO, and GEO?
You need one strategy with two layers. The SEO layer covers technical health, content quality, and links. The AEO/GEO layer adds AI crawler permissions, llms.txt, FAQ and definition content, schema depth, and third-party citations that AI models trust. Since AEO and GEO are the same discipline, there is no meaningful third strategy.
Which should an agency offer first: AEO or GEO services?
They are the same service — the choice is positioning. In most markets 'AEO' resonates when clients ask about ChatGPT and Perplexity visibility, while 'GEO' resonates when the conversation starts from Google AI Overviews. Agencies typically lead with the term their clients are already searching for and deliver a single combined audit and roadmap.
What does GEO stand for in marketing?
In marketing, GEO stands for Generative Engine Optimization — the practice of optimizing content and websites for visibility in generative AI search results such as Google AI Overviews, Gemini, ChatGPT, and Perplexity. It is unrelated to geographic targeting, which is sometimes also abbreviated 'geo' in advertising contexts.