Authority Score

How the eight signals combine

Two of the eight factors do most of the work: link power (the count and quality of your dofollow referring domains, weighted by how authoritative and topically relevant those domains are) and estimated organic traffic (pulled from Semrush’s keyword-position data). The other six are negative “natural profile” checks, spam sanity tests such as no organic rankings despite many links, an unnaturally high share of dofollow domains, an imbalance between links and traffic, or clusters of referring domains sharing one IP or IP network. Because the score also weighs real organic traffic and runs those spam checks, it is harder to game than a links-only number, so sites built on purchased links or spam tend to score lower.

Semrush is explicit about two limits. Scores refresh once every two weeks, so a fresh link takes time to register. And the number is “best used for domain comparison, and not for determining good/bad on an absolute scale,” so a 42 only means something next to a competitor’s 55, not as a pass/fail grade.

It is also not a Google metric. John Mueller has said repeatedly that Google does not use DA or any third-party authority score. Authority Score, Moz’s Domain Authority, and Ahrefs’ Domain Rating are proprietary estimates. They correlate with rankings because they model the same backlink and traffic signals Google reads, not because Google reads them.