GEO, AEO, LLMO - Response engines and generative AI
This category brings together strategies born of generative AI and response engines. The challenge is no longer to obtain a blue link in a list, but to become the textual response generated by the machine.
GEO (Generative Engine Optimization)
GEO refers to being cited as a source in responses generated by AI: ChatGPT, Perplexity, Gemini, or Google's AI Overviews. When an agency talks about AI optimisation, it generally means GEO.
AEO (Answer Engine Optimization)
AEO is older than GEO. It was born in the era of Featured Snippets (zero position on Google) and voice search (Siri, Alexa). Its aim: to provide THE direct answer to a question so that the user doesn't have to click... With generative AI, the logic of AEO remains the same, only the media change (ChatGPT, voice assistants, AI Overviews).
Note: the definition of AEO is evolving. Several major players in the market, including Semrush, now use a broader definition of "AEO" that includes responses generated by AIs (ChatGPT, Perplexity, etc.). Our pedagogical choice in this article is to keep the boundaries of AEO and GEO distinct, so that readers can easily identify each discipline.
LLMO (Large Language Model Optimization)
LLMO is more technical. Unlike GEO, which targets AI responses in real time, LLMO seeks to inscribe your brand directly into the model's 'memory' and knowledge base (GPT-4, Claude) during its training phases.
Comparative table of these 3 terms to understand their difference
Criterion | GEO | AEO | LLMO |
| Primary objective | To be cited as a source in generative AI responses | Become THE direct answer on Google or in voice | Influence the knowledge integrated into AI models |
| Preferred targets | ChatGPT, Perplexity, Gemini, Claude, AI Overviews | Google featured snippets, voice search (Siri, Alexa) | GPT, Claude, Gemini (at model level) |
| Origin | Princeton academic paper (2023) | Featured snippets and voice search (2018-2020) | Technical practices from machine learning |
| Temporality | Rapid effect on responses generated | Rapid effect via Google features | Long-term effect (integration into training) |
| Main lever | Citations, authority, editorial structure | Q/R format, FAQ, schema markup, concise content | Consistency and depth of expertise on the web |
| Indicator of success | Frequency of citations in IA responses | Presence in zero position, in PAA, in voice advertising | Presence in spontaneous model recommendations |
⚠️ Beware of false twins: In France, you will sometimes come across the terms SEO LLM, AISEO or SEO IA. Be careful. They are sometimes used as synonyms for GEO, but they also refer to the opposite: the use of AI to write classic SEO.
If you have to choose just one, choose GEO. It's the most common, the best documented and the one that SEO agencies use most often.