AEO vs GEO vs AI SEO: What's the Difference?

At a glance

• GEO is the most recognized term among marketers and the most used.
• AEO is the term analysts use. Gartner built its vendor category around it.
• AI search optimization (AISO) is what buyers search for and what job postings say.
• AI SEO is the plain-English bridge for SEO teams.
• LLMO is the more technical label, aimed at the models themselves.
• AIO means two different things. Avoid it.

The terms side by side

Where each term came from

AEO is the oldest. It predates large language models and grew out of featured snippets and voice search, when the goal was being the one answer Google or Alexa read out.

GEO came from academia. A 2023 research paper named it and tested how content changes its odds of being cited by a generative engine.

AISO, AI SEO and LLMO came from industry. They were coined by agencies and tool vendors, and none has a single agreed definition.

Which term the market actually uses

The answer depends on who you ask.

• Practitioners favor GEO. In Fractl’s study, reported by Search Engine Land, 84% of marketers recognized GEO, ahead of AEO (61%) and AI SEO (60%), and 42% chose GEO as the one term they use.
• Analysts favor AEO. Gartner’s 2026 research on this category is the Market Guide for Answer Engine Visibility Tools.
• Buyers and hiring managers favor plain language. The same Fractl study found AI search optimization was the most common job-posting label. Koozai’s 2026 research found 74% of marketers had heard of AI search optimisation, against 43% for GEO and 33% for AEO.

Which term should you use?

Use the one your audience uses. Talking to your SEO team, GEO or AI SEO. Writing for a CMO or board, AI search optimization. Evaluating vendors, expect AEO in analyst material and GEO in everything else.

The work underneath doesn’t change: make your pages easy to read and quote, earn mentions on sources the models trust, and track whether you show up.

Other terms you’ll see

These show up less often and don’t need their own definitions:

• LLM SEO: another name for LLMO.
• GAIO (Generative AI Optimization): common in German-language content.
• Answer Search Optimization (ASO): a variant of AEO. Easy to confuse with App Store Optimization.
• SXO (Search Experience Optimization): SEO plus user experience. Older than AI search.
• Search Everywhere Optimization: optimizing across Google, AI assistants, marketplaces and social search at once.
• Share of Answer: another name for AI share of voice.

The bigger picture

All of these terms describe organic visibility. Once AI platforms sell ad placement and agents start completing purchases, organic is one branch of a bigger job. We call that job AI search marketing: organic, paid and commerce together.

See how the Parsnipp GEO / AEO platform tracks visibility across ChatGPT, Gemini, Claude and Perplexity.

Further reading: The GEO industry is right to be skeptical of itself and how to actually start with GEO.