Authority scores: what DR, DA and Trust Flow measure
Third-party authority scores are useful for comparing sites quickly, but none of them is a Google metric. Each tool builds its own model from its own link database.
- Domain Rating (Ahrefs) shows the strength of a site's backlink profile compared with every other site Ahrefs knows, on a logarithmic scale from 0 to 100.
- Domain Authority (Moz) is a 1–100 score that estimates how likely a site is to rank, based on Moz's link data.
- Trust Flow and Citation Flow (Majestic) separate quality from quantity: Citation Flow grows with the number of links, Trust Flow with closeness to a set of trusted seed sites.
Because the scores depend on links alone, they can be inflated. Before trusting a high number, look at real organic traffic, the topics of the linking sites and how the score has changed over time. Use the metrics to compare options, not as a goal in themselves.