Every week, millions of people ask ChatGPT, Perplexity, and Google AI Overviews questions that used to go to Google Search. These AI systems answer directly — and they cite their sources. If your website isn't structured for AI extraction, it won't be cited.

Answer Engine Optimisation (AEO) is the practice of structuring web content so that AI-powered search engines can find, extract, and cite it.

Why AEO matters now

Google's AI Overviews now appear on a significant portion of search queries. ChatGPT's search feature is growing rapidly. Perplexity processes millions of queries daily.

These systems don't show blue links. They synthesise an answer and cite 2-5 sources. If you're not one of those sources, you're invisible — even if you rank on page 1 of Google.

SEO optimises for ranking (appearing in search results)
AEO optimises for citation (being referenced in AI answers)

You need both.

How AI search decides what to cite

Crawl and index your content (also through llms.txt and structured data)
Extract factual claims — specific numbers, definitions, named entities
Cross-reference against other sources for accuracy
Synthesise an answer from multiple pages
Cite only sources that contributed extractable facts

You don't get cited for the best prose. You get cited for the most extractable, factual, and structured content.

The three pillars of AEO

1. Structural signals

JSON-LD structured data — Schema.org markup (Article, Product, FAQPage) on every page
Meta descriptions under 160 characters with specific summaries
Heading hierarchy — one H1, logical H2/H3 nesting
llms.txt — a newer standard providing AI-friendly metadata about your site
AI crawler permissions — allow GPTBot, Claude-Web, PerplexityBot in robots.txt
Freshness signals — datePublished and dateModified in JSON-LD

2. Content signals

Q&A headings followed by concise answers — the most extractable format
Definition sentences — "AEO is the practice of..." gives AI a quotable definition
Lists and tables — easier for AI to parse than dense paragraphs
Factual density — "$99/month for 100 pages" beats "competitive pricing"
Outbound citations — link to authoritative sources (W3C, government sites)
Author attribution — include an author bio

3. Answerability

Self-contained answers — each answer paragraph stands alone without context
Topical focus — one topic per page
Claim support — back every claim with evidence

Before and after

Low AEO score:

We offer flexible pricing plans designed to scale with your business. Contact us to learn more.

High AEO score:

Our Professional plan costs $99/month and includes 100 pages per scan, 100 AI tokens, and API access. Annual billing saves 20%. A free Starter plan supports 10 pages per scan with no time limit.

The second version has specific numbers, answers "how much does it cost?" directly, and stands alone.

Common mistakes

Client-side only rendering. AI crawlers fetch HTML and often don't execute JavaScript. Use SSR for content pages.

Content behind tabs and accordions. Collapsed content may not be indexed. Render critical content as visible HTML.

No structured data. Without JSON-LD, AI systems guess what your page is about. They'll choose a competitor's page that has it.

Vague marketing copy. "Powerful comprehensive solution" tells AI nothing. Replace with specifics.

Blocking AI crawlers. Check robots.txt. If GPTBot and Claude-Web aren't allowed, you're invisible.

How to test your AEO

Pick a question your page should answer
Ask ChatGPT or Perplexity that question
Check if your site is cited
If not, compare your page to the cited sources

The gap is almost always: structured data, specific numbers, and self-contained answers. You can read more about how AEO scoring works or test your site with Blyxo's AEO module.

Quick-start checklist

Add JSON-LD to every public page
Create a /llms.txt file
Allow AI crawlers in robots.txt
Add FAQ sections with self-contained answers
Replace every vague claim with a specific number

AEO is still early. The sites that optimise now will have a significant head start as AI search grows.

AEO is an emerging discipline. If you've been experimenting with AI search optimisation, we'd like to hear what's worked — what signals have you noticed AI systems prioritising?