GEO
Also called: generative engine optimization, generative engine optimisation, LLM optimization, LLMO
Definition
GEO (generative engine optimization) is the practice of increasing how often generative AI tools such as ChatGPT, Gemini, Perplexity and Google's AI Overviews mention your brand or cite your content when they answer questions.
GEO is short for generative engine optimization: the work of showing up in answers written by AI models. It is the same idea as AEO, under a different name. You will also see LLMO (large language model optimization). None of these has a fixed definition, so judge advice by what it actually asks you to do.
How it works
A generative engine answers a prompt by retrieving sources and writing a summary. Your brand gets into that summary in two ways:
- Citation: your page is one of the linked sources. See LLM citation.
- Mention: your brand is named, often because a third-party source the model read (a review site, a comparison article, a Reddit thread) named it. Many of these are unlinked brand mentions.
Each engine favors different sources. Peec AI's March 2026 analysis of about 30 million US citations found these top five:
| Engine | Top cited domains |
|---|---|
| ChatGPT | Wikipedia, Reddit, Forbes, Techradar, LinkedIn |
| Perplexity | Reddit, YouTube, LinkedIn, Wikipedia, G2 |
| Gemini | Reddit, YouTube, Wikipedia, Medium, PCMag / Forbes |
| Google AI Mode | YouTube, Reddit, Facebook, LinkedIn, Yelp |
| AI Overviews | YouTube, Reddit, Facebook, LinkedIn, Medium |
Reddit and YouTube are the only domains in every engine's top five.
Why it matters
Buyers now ask an AI tool for a shortlist before they visit any vendor site. If your brand is not in the answer, you are not on the shortlist. Measurement has caught up: Bing Webmaster Tools added an AI Performance report in February 2026 showing how often your pages are cited in Copilot and Bing's AI summaries, and Google Search Console added generative AI performance reports in June 2026.
How it plays out on Reddit
Because Reddit sits in the top two on every engine in Peec's data, the threads where people compare tools in your category are part of your GEO footprint whether you take part or not. If the top thread for "best invoicing app for freelancers" never names you, the AI answers built on it probably won't either.
The honest fix is to show up in those threads with a useful answer, disclosed if the subreddit asks. BoomReddit flags threads that already rank on Google or get cited in AI answers, which is where a single comment keeps getting read. See Reddit SEO for the full approach.
Common mistakes
- Treating GEO as separate from SEO. Google says its AI features rely on its core ranking systems, and pages must be indexed and snippet-eligible to appear.
- Writing for robots. Google says you do not need to chunk content or rewrite it for AI systems.
- Fake mentions. Seeding your own brand with sockpuppet accounts is astroturfing. Reddit bans it, and Google's guidance says inauthentic mentions are not as helpful as they seem.
Frequently asked questions
Is GEO replacing SEO?
No. GEO depends on SEO: generative engines retrieve pages through search systems first. GEO adds attention to third-party mentions and to which sources each engine trusts.
Which sources do AI engines cite most?
In Peec AI's March 2026 US data, Reddit was the most-cited domain overall, followed by YouTube, LinkedIn and Wikipedia.
Do llms.txt files help with GEO?
Google says Google Search ignores them. Other systems may read them, but no engine has published evidence that they change citation rates.