Generative engine optimization (GEO) is the practice of getting a brand mentioned, recommended and cited inside answers written by AI engines such as ChatGPT, Google AI Overviews, Google AI Mode, Perplexity, Gemini, Microsoft Copilot and Claude. This free handbook explains how those engines choose sources and what you can do about it, one question per chapter. Every claim links to a primary source: Google Search Central, OpenAI, Anthropic, Perplexity, Bing, llmstxt.org and the KDD 2024 GEO paper.
Also known as: answer engine optimization (AEO), AI SEO, AI search optimization, LLM SEO and LLM optimization (LLMO).
- Marketers and founders who want their brand named in AI answers.
- SEO teams adding AI search to an existing program.
- Agencies that need sourced answers for clients.
Each chapter opens with a short, direct answer, then the detail, then its sources.
| # | Chapter | The question it answers |
|---|---|---|
| 1 | What is generative engine optimization (GEO)? | What GEO is, where the term came from and what the work involves |
| 2 | What is answer engine optimization (AEO)? | How AEO relates to GEO and AI SEO |
| 3 | GEO vs SEO | What changes, what stays the same and where the advice conflicts |
| 4 | How AI engines choose sources | Retrieval, query fan-out and how many sources each engine lists |
| 5 | How to get cited by ChatGPT | OAI-SearchBot vs GPTBot vs ChatGPT-User, and what to publish |
| 6 | How to rank in Google AI Overviews and AI Mode | Google's own guidance, quoted |
| 7 | Perplexity, Gemini, Copilot and Claude | What each engine documents about crawlers, controls and reports |
| 8 | Content that gets cited | The KDD 2024 GEO paper's findings and their caveats |
| 9 | Off-site sources: reviews, roundups, Reddit, YouTube and digital PR | How to earn the third-party mentions engines read |
| 10 | llms.txt | What it is, a template, and what Google says about it |
| 11 | Structured data (JSON-LD) for AI search | Copy-paste Organization, Article, FAQPage, BreadcrumbList and Product snippets |
| 12 | How to measure AI visibility | What each metric means, and what Search Console and Bing report |
| 13 | A 30-day GEO plan | A week-by-week first month, with realistic expectations |
| 14 | AI search glossary | Plain definitions of GEO, AEO, query fan-out, grounding and more |
- For Google, GEO is SEO. Google says a page must be "indexed and eligible to be shown in Google Search with a snippet" to appear as a link in AI Overviews or AI Mode, and calls optimizing for its AI features "still SEO" (chapter 6).
- Each engine has its own crawler. Blocking OAI-SearchBot keeps you out of ChatGPT search answers; blocking GPTBot does not (chapter 5).
- Engines list very different numbers of sources. In our open dataset of 138 AI answers (October 2026), ChatGPT listed 17.2 domains as sources per answer and Google AI Mode 2.6 (chapter 4).
- Evidence beats keywords. In the KDD 2024 GEO study, quotations and statistics raised a source's share of the answer; keyword stuffing lowered it (chapter 8).
- llms.txt is optional. Google says Google Search ignores it (chapter 10).
Figures marked as ours come from Cited's AI search citations dataset, October 2026 release: 138 answers to 23 buyer questions about AI search tools and services, each asked once on ChatGPT, Google AI Overviews, Google AI Mode, Gemini, Microsoft Copilot and Claude. The data, method and queries are public, so every figure can be checked. It is one snapshot on one topic, and the chapters say so where it matters.
Use the "Cite this repository" button in the sidebar, which reads CITATION.cff. Or cite it as:
Cited (2026). Generative Engine Optimization (GEO) Guide. https://github.com/Cited-io/generative-engine-optimization-guide
Corrections and additions are welcome, as long as each claim has a source. See CONTRIBUTING.md.
The text of this guide is licensed under Creative Commons Attribution 4.0 International (CC BY 4.0). You may share and adapt it, including commercially, with attribution. Quotations from Google, OpenAI, Anthropic, Perplexity, Microsoft and the GEO paper remain the work of their authors.
Maintained by Cited: AI SEO and GEO agency with its own AI visibility platform. Read more in our guide to generative engine optimization.