How trustworthy and credible a source is judged to be, which shapes whether search engines and AI systems retrieve, rely on, and cite it.
Source Authority is how trustworthy and credible a source is judged to be, which shapes whether search engines and AI systems retrieve it, rely on it, and cite it. It is built from signals like demonstrated expertise, a track record on a subject, references and links from other respected sources, and factual consistency over time.
In AI answers, authority acts as a filter on what a model trusts. Among the pages it retrieves to ground a response, a system leans harder on sources it treats as authoritative and discounts the rest, a tendency we study as grounding bias. A page can be relevant and still lose its place in an answer to a more authoritative source saying the same thing.
Source authority is about a specific source or domain, distinct from brand authority, which is how much space a brand occupies in a model's memory. The two reinforce each other: sources cited and trusted across the web are also the ones a model has seen most, so earning authority is a direct route to AI visibility.
