AEO, answer engine optimisation, earns the direct answer a search engine shows above or instead of a list of links. GEO, generative engine optimisation, earns a mention inside answers written by AI systems such as ChatGPT, Gemini and Perplexity. All three rest on one foundation: a website a machine can reach, read and attribute to a real business.
In the Crane Index™ scan of 1 October 2026, 54% of 2,295 websites had no Organisation markup to say who they are, 64% had no sameAs links to confirm it, and 191 of 2,207 refused at least one AI agent at the edge. Every check, counted.
The short answer
| SEO | AEO | GEO | |
|---|---|---|---|
| Stands for | Search engine optimisation | Answer engine optimisation | Generative engine optimisation |
| The goal | Rank in the list of results | Be the answer a search engine shows directly | Be named or cited in an AI-written answer |
| Where it shows | Google and Bing results | Featured answers, AI Overviews, voice answers | ChatGPT, Gemini, Perplexity, Copilot, AI Mode |
| What success looks like | Clicks from search | Your wording used as the answer | Your business named, ideally with a link |
| How it is measured | Search Console: impressions, clicks, position | Partly in Search Console, partly by hand | Mostly by asking the engines a fixed set of questions over time |
Where the three overlap
Most of the work is shared. A machine that ranks a page, a machine that lifts an answer from it and a machine that writes a summary naming it all need the same things first: to be allowed in, to find real content without running a pile of JavaScript, and to be sure which business the page belongs to.
- Pages the crawlers can reach, in robots.txt and at the firewall.
- Content present in the page itself, not assembled later in the browser.
- A clear statement of who the business is, in Organisation markup with sameAs links to its other profiles.
- Plain answers to the questions buyers actually ask, written as sentences that still make sense quoted on their own.
- Named, credentialed people behind the content.
Where they differ
The differences are in what the machine does with the page. A search engine ranks it and sends a click. An answer engine lifts one passage and may send no click at all. A generative engine reads several sources, writes its own summary and decides which businesses to name. So the measure of success moves from visits, to being the quoted passage, to being named.
That last shift matters for a business owner. An AI answer can recommend you without anyone visiting your site, and can recommend a competitor without you ever seeing the question. Neither shows up in your analytics.
Is GEO just SEO with a new name?
Partly. Anyone selling GEO as an entirely new discipline is overselling it, and anyone dismissing it as SEO with a new label is missing three things that matter more for AI answers than for rankings: whether the business is unambiguous as an entity, whether its claims are specific enough to quote, and whether AI crawlers are let in at all. A site can rank well and still be turned away at the edge by bot protection that only AI agents trip.
What to do first
- Check that AI crawlers can reach the site, in robots.txt and at the edge. The free Crane Index scan checks both.
- Declare who you are: Organisation markup, a logo, contact details and sameAs links to your Google Business Profile, Companies House record and social profiles.
- Mark up what you sell as a Service or Product, with the area you serve.
- Rewrite your key pages so each one answers the question a buyer would type, in its first sentence.
- Put a named person, with their credentials, behind the advice on the site.
How to measure each one
SEO is the easiest: Google Search Console shows impressions, clicks and average position for every search you appear in. AEO is partly visible there too, because AI Overviews are counted in Search Console's web results. GEO has no equivalent console. The reliable method is to ask the engines the same set of buyer questions on a fixed schedule and record whether, and how, your business is named. That is what Crane Intelligence™ does.