// resources · basics

What is GEO? Generative Engine Optimization explained

by Johannes Zimmer · · 6 min read · GEO
In short

GEO (Generative Engine Optimization) is the practice of optimising a website so AI answer engines like ChatGPT, Google AI Overviews, Perplexity and Gemini can read, understand, cite and recommend its content. SEO targets rankings in classic search; GEO targets being part of the generated answer itself.

TL;DR
  • GEO means being visible in AI answers, not just in ten blue links.
  • Technical basis: semantic HTML, Schema.org, llms.txt, crawler access and an answer-ready structure.
  • More than half of global web traffic is already non-human (Imperva 2025).
  • GEO complements SEO, it doesn't replace it.

What does GEO actually mean?

GEO stands for Generative Engine Optimization: preparing a website so generative answer systems use it as a reliable source. These systems answer questions directly instead of just listing links. Whoever appears in the answer gains visibility; whoever is poorly machine-readable drops out before a human ever sees the page.

GEO vs. SEO: what's the difference?

SEO gets you into the results list. GEO gets you into the answer. SEO thinks in rankings and clicks; GEO thinks in citations and mentions. The technical groundwork overlaps (clean HTML, fast pages, clear structure), but GEO additionally requires machine-readable meaning: structured data, llms.txt and content that works as standalone answer blocks.

Why is GEO becoming important now?

Because who reads a website is shifting. In 2024, automated traffic overtook humans for the first time in over a decade: 51% of global web traffic is bots and crawlers (Imperva 2025). The fastest-growing part of that is AI crawlers and agents. And it's accelerating: Gartner expects AI agents to handle around 90% of B2B purchases by 2028 (Gartner 2025). More on our agentic web page.

How do you make a website AI-ready?

Four building blocks form the basis:

  • Semantic HTML — real heading hierarchy, tables and landmarks so machines recognise structure.
  • Schema.org / JSON-LD — structured data that answer engines consume directly.
  • llms.txt & crawler access — AI bots (GPTBot, ClaudeBot, PerplexityBot, Google-Extended) find and may read the right thing.
  • Answer-ready structure — direct answer first, clear definitions, Q&A blocks, citable statements.

How do you measure GEO success?

Via a per-page readiness score (how good is machine-readability?) and via actual mentions in AI answers. Monitoring tools show the status; implementation closes the gap. That implementation is exactly what flize delivers as patches into the dev team.

FAQ

Is GEO the same as SEO?

+

No. SEO optimises for placements in the classic results list. GEO optimises for AI answer engines using and citing your content as a source. The techniques overlap; the goal differs.

Do I need GEO if I already do SEO?

+

Yes. Good SEO is a solid foundation but doesn't cover what answer engines additionally need: machine-readable structure, llms.txt, citable answer blocks and crawler access for AI bots.

What is llms.txt?

+

llms.txt is a file in your website root that shows AI systems compactly which content matters and how it's structured, similar to robots.txt, but for language models.

How do I start with GEO?

+

Start with a readiness test of one important page: how good are semantic HTML, Schema.org, llms.txt and crawler access? That yields a prioritised list of what to implement first.

Johannes Zimmer
Johannes Zimmer is the founder of flize (sitebrunch GmbH) and helps agencies make websites machine-readable and AI-agent-ready.

Test your first page.

Sign up, 2 credits free, check a domain's GEO readiness right away. No credit card.

Start for free