GEO vs SEO vs AEO: What Actually Differs, and What Does Not

The short answer

SEO gets you ranked. GEO gets you quoted. AEO gets you used as the answer. They are three names for optimising the same website against three different ways a person can find it, and the honest position is that they overlap far more than the industry admits.

The practical difference is what counts as success. In SEO, success is a position on a results page and a click. In generative engine optimization, success is being cited inside an AI-written answer, whether or not anyone clicks. In answer engine optimization, success is your content being the answer, in a featured snippet, a voice result or an AI summary.

What each term actually means

SEO

Search engine optimization is the original discipline: make a page that a search engine can crawl, understand and rank, so a human clicks through. Everything downstream still depends on it. If a crawler cannot reach your page, no amount of AI-era tactics will save you.

GEO

Generative engine optimization is optimising to be cited by systems that write an answer rather than list links. The term was coined in a 2023 academic paper and has been adopted, loosely, by the industry since. The work is mostly about making individual passages quotable: self-contained, factual, attributable.

AEO

Answer engine optimization predates GEO and originally described optimising for featured snippets and voice assistants. It has since been stretched to cover AI answers too, which is why AEO and GEO are now used almost interchangeably. If someone uses them as synonyms, they are not really wrong.

You will also meet AIO, LLMO, SGE optimisation and a few others. None of these are standards. They are marketing labels for overlapping work, and the labels change faster than the practice does.

Where they genuinely differ

1. The unit of success

This is the difference that actually changes what you do. SEO optimises a page to rank. GEO optimises a passage to be lifted. A page can rank tenth and still be the paragraph an AI quotes, and a page can rank first and never be cited once. If you only measure rank, you cannot see that happening.

2. Whether a click happens at all

SEO assumes the click is the prize. AI answers frequently resolve the question without one, so the value shifts from traffic to being named. That is uncomfortable for anyone whose reporting is built on sessions, and it is the single biggest reason the two disciplines feel different in practice even where the tactics coincide.

3. How you measure it

Search Console gives you rank and clicks. It gives you nothing about whether ChatGPT cited you. Measuring GEO means tracking citations and brand mentions across engines, which needs different tooling. You can check how visible your site currently is to AI engines as a starting point.

Where they overlap more than the marketing suggests

This is the part most comparison articles skip, because there is less to sell in it.

• Crawlability: if a bot cannot fetch the page, nothing else matters. Identical requirement across all three.
• Structured data: schema markup helps search engines and AI systems parse meaning. Same work, two beneficiaries.
• E-E-A-T signals: experience, expertise, authoritativeness and trust drive both ranking and citation selection.
• Clear writing: leading with the answer helps featured snippets, AI citation and human readers at the same time.
• Content freshness: stale content is discounted by both ranking systems and generative ones.

Most of what agencies sell as a GEO programme is competent technical SEO plus clearer writing. That is not a criticism of the work, which is usually worth doing. It is a caution against paying twice for it.

Do you need a separate GEO strategy?

Probably not a separate strategy. Probably yes to separate measurement.

The tactics largely converge, so running two programmes duplicates effort. What genuinely does not exist in your current stack is visibility into AI answers, because Search Console will never report it. Add the measurement first, then decide whether the gap it reveals justifies dedicated work.

Be sceptical of anyone selling GEO as a distinct channel with guaranteed lift. As a worked example, llms.txt is widely marketed as an AI ranking factor. Google confirmed in July 2025 that Search does not use it, and OtterlyAI measured 62,100 AI bot visits across 90 days of which only 84, or 0.1%, fetched the file. It is still worth publishing, because it is nearly free and because coding agents genuinely read it. It is simply not the lever it is sold as.

What to do next

In order, and none of this requires abandoning SEO:

• Measure the gap. Run an AI visibility check so you know whether the problem is real for your site before you spend on it.
• Fix crawl access. Confirm GPTBot, ClaudeBot, PerplexityBot and Google-Extended are not blocked in robots.txt.
• Rewrite your top pages to lead with the answer. This serves ranking, snippets and citation simultaneously.
• Add or repair structured data on the pages that matter commercially.
• Publish something only you can publish. Original data is the most reliably cited content type.

If you want the detail on the third and fourth of those, the GEO guide goes step by step, and the free llms.txt generator and validator handles the file itself.