Citation rate, in the context of AI search and large language models, refers to the proportion of AI-generated answers that include a direct attribution or source link to a given website or piece of content. It is an emerging key performance indicator for practitioners of Answer Engine Optimisation and Generative Engine Optimisation, analogous to click-through rate in traditional SEO but measured across AI surfaces such as Perplexity, Google AI Overviews, ChatGPT Search, and Bing Copilot. A higher citation rate indicates that AI systems are grounding their responses in your content, which may sustain referral traffic even when users do not click through to read the full article. Citation rate is influenced by factors such as content authority, factual precision, source corroboration, structured data markup, and how closely a page’s text matches the phrasing of common user queries. Tracking tools specifically designed to monitor LLM citations began appearing in 2024.