AEO: How to Optimize for ChatGPT and LLM Citations

Traditional SEO is no longer enough. With the rapid growth of ChatGPT, Perplexity, Gemini and other language models, more and more people are getting direct answers without needing to click on a search result. For digital marketing and SEO professionals, this represents both a challenge and a massive opportunity.

In this article we explain what AEO (Answer Engine Optimization) is, why it’s critical for 2025, and how to start implementing it.

What is AEO (Answer Engine Optimization)?

AEO is the set of optimization practices aimed at getting AI-based answer engines (LLMs like ChatGPT, Gemini or Perplexity) to cite your content as an authoritative source when answering user questions.

Unlike traditional SEO which aims to rank in search engine results pages (SERPs), AEO seeks to appear directly in AI-generated responses.

Why Does AEO Matter in 2025?

According to recent studies, more than 40% of informational searches in the United States already go through generative AI tools before reaching a traditional search engine. This percentage is growing month by month.

The implications for brands are clear: if you don’t appear in LLM responses, you’re losing visibility to a growing portion of your potential audience.

The 5 Pillars of AEO

1. Reinforced E-E-A-T

Google and AI models prioritize content that demonstrates Experience, Expertise, Authoritativeness and Trustworthiness (E-E-A-T). For LLMs, authority signals include:

• Mentions and citations on other high-authority websites
• Clear and verifiable author profiles
• Consistent and accurate content history
• Presence on Wikipedia and reference sources

2. Structured Data (Schema.org)

Correct Schema.org implementation is fundamental. The most relevant types for AEO are:

• FAQPage — direct questions and answers
• HowTo — step-by-step guides
• Article and NewsArticle — editorial content
• Organization and Person — entity information
• Product and Service — for brands and businesses

3. Direct Answer Format

LLMs favor content that answers questions directly and concisely. Best practices include:

• Answering the main question in the first 2-3 paragraphs
• Using headers that are questions or clear statements
• Including lists and tables for structured information
• Keeping paragraphs short (maximum 3-4 sentences)

4. Topic Depth (Topic Clusters)

AI models favor sources that demonstrate depth and breadth in a topic. This is achieved with:

• Pillar articles that cover a topic in depth
• Supporting content addressing related subtopics
• Consistent internal linking between articles in the same cluster
• Regular updating of existing content

5. Technical Citability

To be cited by LLMs, your site must be technically accessible and semantically rich:

• Correct semantic HTML (hierarchical headings, lists, tables)
• llms.txt — file that tells LLMs how to index your site
• High loading speed (impacts frequent crawling)
• Unique and original content (LLMs detect duplicates)

Differences Between SEO and AEO

Aspect	Traditional SEO	AEO
Goal	Rank in SERP	Be cited by LLMs
Format	Keyword density	Direct answers
Structure	Running text	Semantic data
Authority	Backlinks	E-E-A-T + mentions
Metrics	CTR, position	Citations, AI share of voice

How to Measure AEO Impact

Measuring LLM citations is still an emerging area, but there are some practical ways:

1. Manual searches — regularly test relevant queries in ChatGPT, Perplexity and Gemini
2. Specialized tools — platforms like Seodiag are incorporating AI visibility metrics
3. Branded traffic — direct traffic and brand searches often increase when you appear in LLM responses
4. Mentions and backlinks — LLM citations frequently generate secondary backlinks

First Steps to Implement AEO

If you’re starting out, we recommend this sequence:

1. Audit your current content with a tool like Seodiag to identify semantic structure gaps
2. Implement FAQPage schema on your most important pages
3. Create an llms.txt at your domain root
4. Rewrite your pillar pages with direct answer format
5. Reinforce author profiles throughout the site

AEO doesn’t replace traditional SEO — it complements it. Brands that understand this first will have a significant advantage in the coming years.

---

Want us to audit your site to identify AEO opportunities? Talk to our team or try Seodiag for free.