Guide

Answer engine optimization: how to get cited by AI

Answer engine optimization (AEO) is the practice of making your website easy for AI assistants — ChatGPT, Gemini, Claude, Perplexity and Google's AI Overviews — to read, understand and cite when people ask questions. Where classic SEO fights for a blue link, AEO aims to be the source an answer is built from. You'll also see it called generative engine optimization (GEO).

How answer engines choose sources

Answer engines combine what a model learned during training with pages fetched at question time. To be used, a page has to clear three hurdles: the engine's crawler must be allowed to fetch it, the content must be parseable and unambiguous, and the engine must be confident about who you are and what you offer. AEO work maps directly onto those three hurdles.

1. Let AI crawlers in

Many sites block AI crawlers without realising it, through a blanket rule or a default from their host. Check your robots.txt for the main agents: GPTBot and OAI-SearchBot (OpenAI), Google-Extended (Gemini), ClaudeBot (Anthropic) and PerplexityBot. Explicitly allowing them looks like this:

User-agent: GPTBot
Allow: /

User-agent: ClaudeBot
Allow: /

User-agent: PerplexityBot
Allow: /

Sitemap: https://example.com/sitemap.xml

2. Publish an llms.txt file

llms.txt is a proposed standard: a short markdown file at the root of your site that summarises what you do and points to the pages most worth reading. It's not yet used by every engine, but it's cheap to add and gives models a clean, curated map of your site.

# Example Co

> Example Co makes scheduling software for dental clinics.

## Key pages
- [Pricing](https://example.com/pricing): plans and costs
- [Docs](https://example.com/docs): setup guides

3. Add structured data

Schema.org JSON-LD states facts in a machine-readable form instead of leaving the engine to infer them. Start with Organization markup on every page (name, URL, logo, social profiles), then add Product, Article or FAQ markup where the page genuinely contains that content.

4. Write for clear, quotable answers

Engines lift self-contained passages. Put a direct one- or two-sentence answer near the top of a page, use descriptive headings that match how people phrase questions, and keep titles and meta descriptions specific. Name your brand and category consistently so the engine can connect your site to the right entity.

5. Measure whether you're being cited

Technical readiness is necessary but not sufficient. Test the questions your buyers actually ask — short, casual queries like "best crm for small business" — and check whether your brand is mentioned, and which competitors are cited instead. Each miss points to a page or answer you're missing.

AEO vs SEO

They overlap heavily: crawlability, clear content and authority help both. The difference is the goal. SEO measures rankings and clicks; AEO measures whether AI answers mention and cite you, often without a click at all.