Domain Authority

Domain Authority is a metric developed by Moz that estimates how likely a domain is to rank in search results based primarily on the quantity and quality of links pointing to it. It aggregates link signals across an entire domain into a single score, treating all pages as part of one authority pool. The metric uses a machine-learning model trained against Google's actual rankings, though it is not a Google metric and does not directly influence rankings.

SEOs use Domain Authority as a quick proxy for domain strength when evaluating link targets, competitors, or the value of a backlink opportunity. A higher-DA site linking to you is generally seen as a stronger endorsement. However, the score is relative and non-linear—the difference between a DA of 20 and 30 is not the same as between 70 and 80.

In practice, Domain Authority has limitations: it ignores topical relevance, content quality, and on-page factors; it can be gamed through link schemes; and it lags behind actual ranking shifts. Most practitioners treat it as a rough initial filter rather than a definitive measure of a site's true ranking power or the actual lift a link will provide.