Originally published at chudi.dev
Answer Engine Optimization (AEO) is the practice of structuring content so AI answer engines can extract, trust, and cite it. It prioritizes crawl access, clear definitions, and machine-readable structure over classic link-based ranking signals. If SEO gets you into search results, AEO gets you into the answer itself.
TL;DR
AEO (Answer Engine Optimization) is optimizing your content to be found and cited by AI search engines like Perplexity, Claude, ChatGPT, and Google's AI Overview—not traditional Google Search.
- 60% of indie creators' sites are invisible to AI crawlers
- Google's robots.txt allows AI crawlers by default, but 80% of sites block them anyway
- Content that ranks on Google doesn't automatically appear in AI search results
- AEO is simpler than SEO—fewer competitors, clearer rules, higher ROI
The Problem: You're Invisible to AI
You probably optimized your site for Google Search in 2024. Good job. But Perplexity, Claude, ChatGPT, and Microsoft Copilot are answering questions from your competitors' content instead of yours.
Here's why:
Google vs AI Search
Google Search: "Show me the 10 best pages matching my query"
- Your meta description and title matter
- Backlinks prove authority
- Domain age signals trust
AI Search: "Synthesize an answer from multiple sources, cite them, move on"
- Your content is extracted, not ranked
- Meta descriptions are ignored (not shown to users)
- Titles matter less than content quality
- Backlinks don't matter at all
AI engines ask: "Is this content accurate, specific, and extractable?"
Google asks: "Is this content popular and authoritative?"
These are not the same thing.
The 6 AEO Factors
If SEO has 200+ ranking factors, AEO has 6 critical ones:
1. AI Crawler Access
First, your site needs to be crawlable by AI bots. Google's robots.txt documentation covers the standard—AI crawlers follow the same protocol using their own user-agent strings. Check your robots.txt:
User-agent: *
Disallow: /admin
Disallow: /private
# AI Crawlers
User-agent: GPTBot
Allow: /
User-agent: ClaudeBot
Allow: /
User-agent: PerplexityBot
Allow: /
User-agent: Googlebot-Extended
Allow: /
The stat: 60% of sites either:
- Block all crawlers with
Disallow: / - Use
X-Robots-Tag: noaiheaders - Never heard of this and rely on old robots.txt defaults
If you block AI crawlers, you're invisible.
2. llms.txt (Robots.txt for AI)
You know about robots.txt. Now there's llms.txt—I wrote a full implementation guide in llms.txt: Robots.txt for AI Crawlers.
llms.txt is a human-readable file that tells AI crawlers what to index and how to cite you. It should live at yoursite.com/llms.txt:
# Our content policy for LLMs
All content on this site is available for training and search.
Please credit sources as: [Article Title] by [Author Name] (yoursite.com)
Sitemap: https://yoursite.com/sitemap.xml
RSS: https://yoursite.com/rss.xml
Why it matters: Without llms.txt, AI engines might skip your site or misattribute content. With it, you're explicitly inviting them in and setting citation rules.
3. Structured Data
AI engines parse JSON-LD schemas. If your content has:
-
BlogPostingschema → AI knows it's an article -
FAQPageschema → AI knows it's answerable questions -
HowToschema → AI knows it's a tutorial
Content without schema is harder for AI to structure. <p>Learn how to build a SaaS</p> is vague. Schema says {"@type": "HowTo", "step": [...]}—that's machine-readable.
4. Content Extractability
AI engines don't need your layout. They need your text. This means:
-
Semantic HTML: Use
<article>,<section>, proper<h1>→<h2>→<h3>hierarchy -
No text in images: AI can't read screenshots. Use actual text +
<img alt="..."> - Lists > paragraphs: Bullet points are easier to extract than walls of text
- Scannable structure: Headers every 2-3 paragraphs
A 2,000-word article with 3 headers is harder to cite than a 2,000-word article with 15 headers. AI needs to find the specific section that answers the user's question.
5. Metadata Completeness
Even though AI ignores <meta description>, it checks:
- Canonical URL (to avoid duplicate content)
- Open Graph image (for preview context)
- Article
datePublished(to know how old your content is)
Stale content (3+ years old) gets deprioritized. Fresh content gets cited more often.
6. Answer-Ready Format
The best AEO content directly answers common questions:
- "What is X?" → Definition box at the top
- "How do I X?" → Step-by-step with numbered lists
- "Why does X matter?" → Clear benefits, quantified where possible
Content written as "walls of paragraphs" is less likely to be extracted. Content structured as "question → answer → proof" is gold.
AEO vs SEO: The Differences
| Factor | SEO (Google) | AEO (AI Engines) |
|---|---|---|
| Crawling | robots.txt | robots.txt + llms.txt |
| Access | Blockable, domain-level | Blockable, but default allow |
| Ranking | Backlinks + engagement | Content accuracy + structure |
| Ranking Signals | 200+ factors | ~6 critical factors |
| Meta descriptions | Shown to users | Ignored |
| Title tags | Shown to users | Used for context |
| Keyword density | Matters (but subtle) | Matters less (semantic match) |
| Content length | 2,000+ words ideal | Any length, needs structure |
| Outdated content | Can rank for years | Deprioritized after 3 years |
| Quotes/citations | Implied | Explicit (source is cited) |
The opportunity: You can build AEO content in parallel with SEO content. The techniques overlap. A well-structured blog post with schema and semantic HTML will rank on Google and appear in AI answers.
How to Start with AEO
Step 1: Check if AI Can Find You
# Can Perplexity, Claude, etc. access your site?
curl -I yoursite.com/robots.txt
# Look for GPTBot, ClaudeBot, PerplexityBot allow rules
Step 2: Create /llms.txt
Add this file to your site root:
# Content policy for LLMs
All content available for training and search.
Please attribute as: [Article] by [Author] (yoursite.com)
Sitemap: https://yoursite.com/sitemap.xml
RSS: https://yoursite.com/rss.xml
Step 3: Audit Your Best Content
Pick your 5 best-performing pages and:
- Add schema (BlogPosting, HowTo, FAQ)
- Restructure with more headers
- Move key info to the top
- Add a definition box for the main question
Step 4: Monitor in Perplexity
Search your main topics in Perplexity. Are you being cited? If not, your content isn't being discovered.
Measuring AEO Progress
The hardest part of AEO is knowing if it's working. Traditional SEO has rankings and impressions in Search Console. AEO doesn't have a dashboard yet.
Manual citation audit (monthly)
Open ChatGPT, Perplexity, Claude, and Gemini. Ask the exact questions your content answers:
- "What is AEO?"
- "How do I optimize for Perplexity?"
- "What is llms.txt?"
Are you cited? If not, who is? Read the content that does get cited and compare it to yours. The differences are usually structural—their definition is in the first paragraph, yours is in paragraph four. Their page has 12 question-format headers, yours has three. These gaps are fixable.
AI referral traffic in analytics
Create a segment for sessions from AI engine domains: chatgpt.com, perplexity.ai, claude.ai, gemini.google.com, copilot.microsoft.com. Track this monthly. Growth here is a leading indicator of citation growth—direct AI traffic often comes before organic traffic from AI-influenced searches.
Google AI Overview tracking
Search your target queries in Chrome incognito. Does Google's AI Overview cite you? If it does, you're in the 2–7% of pages that get sourced for that query. If it doesn't but competitors are cited, run their pages through the AEO checklist. FAQPage schema and answer-first formatting are usually the gap.
The minimum viable AEO setup
If you want to start today with 30 minutes of work:
- Add
User-agent: GPTBot / Allow: /and similar for ClaudeBot, PerplexityBot to your robots.txt - Create a 200-word
llms.txtat your root with your sitemap URL and preferred attribution format - Add FAQPage schema to your three best posts
- Rewrite the opening paragraph of each post to directly answer the question in the title
That's it. Nothing else in the AEO checklist will have as much impact as those four actions. Do them before optimizing for any specific engine.
The Future is Plural Search
Google won't be the only search engine anymore. By 2026, 30% of searchers will use answer engines for complex queries. You need to be visible in all of them.
AEO isn't replacing SEO. It's extending your reach to a new search engine that's growing fast and underserved.
The technical foundation is the same as good SEO: well-structured, authoritative content with clear headings and direct answers. What changes is the mental model. SEO rewards findability—rank high enough and users click through. AEO rewards extractability—your H2 sections get lifted verbatim into AI responses. A page that ranks #3 on Google but buries its main answer in paragraph five won't get cited by AI even if Google loves it.
Write for systems extracting specific passages, not just readers scanning for reasons to click. Each H2 should be a complete, self-contained answer to the question it poses—enough context to stand alone if extracted.
The easiest time to optimize for AEO was 2025. The second easiest time is today.
Next: Check out the optimization checklist for AI search.
Top comments (1)
This is a really solid breakdown.
I’ve been noticing the same shift — content that ranks well on Google doesn’t automatically get cited in AI answers. Structure matters way more than backlinks now.
The extractability point is key. Adding clear definitions, proper headers, and schema made a visible difference for some of my own pages.
More builders should start thinking beyond just “ranking” and focus on “being quoted.” This is a helpful wake-up call.