Domain Authority (DA)
Domain Authority (DA) is Moz's 1-to-100 predictive score estimating how likely a website is to rank in search results.
DA is built from Moz's link index and a machine-learning model trained against actual search rankings, blending signals like linking root domains and overall link profile quality. Like other vendor metrics, it is logarithmic, so gains get harder at the top of the scale. It is best used comparatively, to weigh one domain against another, not as a precise grade.
DA is frequently confused with Google's authority, but it is a Moz estimate and not used by Google. It serves the same prospecting purpose as Ahrefs' domain rating (DR), and the two often disagree because each vendor crawls a different link index and uses a different formula. Moz's page-level counterpart is page authority (PA).
The honest caveat: because DA is link-based and modelable, it can be manipulated, and sellers sometimes advertise inflated DA from cheap link blasts. A genuinely useful link comes from a relevant site with real organic traffic and a clean spam score, so verify those alongside DA rather than treating the number as the deciding factor.