Foundations · 8 min read
GEO vs AEO vs LLMO vs AIO: What's the Difference?
The AI search optimization industry has no standard vocabulary. The same work is sold under at least seven names. Here is a map so you can stop guessing.
The short answer
GEO, AEO, LLMO, AIO, AI SEO, GXO, and AISO mostly describe the same goal — getting your brand cited by AI search engines — with small differences in emphasis and origin.
GEO is the most widely used term in 2026 and the one we use as our primary label. The others are largely overlapping, with a few meaningful distinctions worth knowing before you hire anyone.
The terms, defined
Here is each term, what it emphasizes, and who tends to use it.
- GEO (Generative Engine Optimization) — citation in AI-generated answers. The dominant 2026 term.
- AEO (Answer Engine Optimization) — older term from the featured-snippet and voice-search era, repurposed to include AI answers.
- LLMO (Large Language Model Optimization) — a technical framing focused on how LLMs retrieve and cite via training data and RAG.
- AIO — ambiguous: either an umbrella for GEO+AEO+LLMO, or Google's 'AI Overviews.' Context decides.
- AI SEO — ambiguous: either optimizing for AI engines, or using AI tools to do traditional SEO faster.
- GXO (Generative Experience Optimization) — newer, focused on the full experience inside an AI answer.
- AISO — a rarely used synonym for GEO.
Frequently asked questions
Which term should my company use?
Use GEO as your primary term — it has the widest recognition in 2026 — but include AEO, LLMO, and AI SEO in your content so you are found regardless of which name a prospect searches.