Citation Flow is a proprietary link metric from Majestic SEO that measures the volume of links pointing to a website, regardless of their quality. It scores sites from 0 to 100 based purely on how many other URLs link to them, following a logic similar to PageRank’s raw link count. A high Citation Flow score indicates a heavily linked-to site, but it reveals nothing about whether those links come from reputable sources. Citation Flow is most useful when compared against Trust Flow: a site with high Citation Flow but low Trust Flow has acquired many links of questionable quality — often a sign of link spam. The ratio of Trust Flow to Citation Flow (sometimes called the “trust ratio”) is a quick heuristic used by link-builders to assess whether a prospective link source has a natural, healthy link profile.