What is Answer engine optimisation?
Answer engine optimisation (AEO) is the practice of structuring a website so AI assistants like ChatGPT, Perplexity, Gemini and Google's AI Overviews can quote it accurately when someone asks a question.
Also called: AEO, AI search optimisation, generative engine optimisation.
Classic SEO tries to win a click from a list of ten blue links. AEO accepts that a growing share of searches never produce a click at all: the assistant reads a handful of pages, writes an answer, and cites its sources. If your page is one of those sources, you get the credibility and often the visit that follows. If it isn't, you are invisible even when you rank.
The mechanics are less mysterious than they sound. Answer engines favour pages that state a claim plainly near the top, use headings that read like real questions, keep facts in text rather than images, and back everything with structured data the machine can parse without guessing. They also strongly prefer pages that load and render on the server, because a crawler that has to execute JavaScript often simply doesn't.
The uncomfortable part is that AEO rewards clarity over cleverness. A page that answers "how much does an emergency plumber cost in Leeds?" in the first two sentences will be quoted ahead of one that spends four paragraphs on brand storytelling first.
What to actually do about it
- Put a one or two sentence answer directly under each heading, before the detail.
- Write headings as the question a customer would actually type or say.
- Add FAQ structured data to pages that answer several distinct questions.
- Keep prices, opening hours, service areas and contact details in real text.
- Publish an llms.txt file so assistants can find your key pages quickly.
Koo writes pages in this shape by default — question-style headings, a lead answer, FAQ and organisation schema, a generated llms.txt, and server-rendered HTML — so AEO is the standard build rather than a later retrofit.
Related terms
Schema markup
Schema markup is a block of machine-readable data added to a web page — usually as JSON-LD — that tells search engines and AI assistants exactly what the page is about: a business, a product, an article, a review, a set of questions.
llms.txt
llms.txt is a plain-text file at the root of a website that gives AI assistants a curated, markdown-formatted map of its most important pages, so a model can find the substance without crawling and parsing the whole site.
Long-tail keyword
A long-tail keyword is a longer, more specific search phrase with lower search volume but clearer intent and far less competition — for example "repair a leaking radiator valve in Leeds" rather than "plumber".