LLM citation
Also called: AI citation, cited by ChatGPT, AI source citation, citation in AI answers
Definition
An LLM citation is a link to a web page that an AI assistant, such as ChatGPT, Perplexity, Gemini or Google's AI features, shows as a source for its answer, signaling the page was retrieved and used.
An LLM citation is a source link inside an AI-generated answer. When Perplexity puts a numbered reference after a sentence, when ChatGPT lists pages under Sources, or when an AI Overview links a page, each of those is a citation.
Citations matter because they are the part of an AI answer you can measure and click.
How it works
Modern AI search runs on retrieval-augmented generation. Google describes it in its 2026 guide: the system retrieves relevant pages from a search index, reviews the specific information in them and writes a response with links to pages that support it.
Two events happen, and they are not the same:
- Retrieval: your page enters the candidate set the model might use.
- Citation: the answer actually uses and references it.
Peec AI's February 2026 study of more than 1 million citations found that on Perplexity, 64% of retrieved URLs were never cited. Being found is necessary but not sufficient. Pages that answer a specific sub-question clearly tend to make the cut.
A brand can also be named without being cited, when the model repeats what a third-party source said. That is an unlinked brand mention, and it counts toward AI visibility even though no link points to you.
How to measure it
- Bing Webmaster Tools (AI Performance, February 2026): total citations, average cited pages, page-level citation counts and grounding queries, the phrases the AI used when it retrieved your content.
- Google Search Console (generative AI performance reports, 2026): impressions for your URLs in AI Overviews, AI Mode and Discover AI features.
- Prompt tracking tools: run buyer questions across engines and log which domains get cited.
How it plays out on Reddit
Reddit is the most-cited domain in AI search across ChatGPT, Google AI Mode, Gemini, Perplexity and AI Overviews, based on Peec AI's analysis of about 30 million US citations in March 2026. Google (February 2024) and OpenAI (May 2024) both signed deals to use Reddit's Data API.
That means a large share of the citations for "best X" and "X vs Y" questions point to Reddit threads, not vendor sites. You cannot make a thread cite you, but you can be in it. A specific, useful comment in a thread that AI tools keep citing gets read by every model that retrieves it. BoomReddit flags threads that already rank on Google or get cited in AI answers, which is where one good reply keeps working. See Reddit SEO.
Common mistakes
- Counting citations without reading them. A citation to a thread that criticizes you is still a citation.
- Treating one run as truth. AI answers vary. Measure the same prompts repeatedly.
- Over-optimizing the format. Google says you do not need to chunk or rewrite content for AI systems. Clear writing is enough.
Frequently asked questions
What is the difference between an LLM citation and a mention?
A citation links to a source page. A mention names your brand in the answer text, with or without a link to you.
How do I get cited by ChatGPT or Perplexity?
Be indexed and crawlable by their search systems, publish specific answers to the questions buyers ask, and be present in the third-party sources they cite most, which often include Reddit.
Can I see how often my site is cited in AI answers?
Partly. Bing Webmaster Tools and Google Search Console both report AI feature visibility for your own URLs. Mentions inside other sites' citations need prompt tracking.