Domain Authority (DA)

Technical explanation

Domain Authority is calculated by Moz using a machine learning model that evaluates multiple factors, primarily the quantity and quality of external backlinks pointing to a domain. The score uses a logarithmic scale from 1 to 100, meaning it is progressively harder to improve at higher levels. DA is calculated by aggregating link data from Moz's web index (Link Explorer), considering linking root domains, total link count, and link quality signals. The model is periodically updated, which can cause score fluctuations unrelated to any change in the domain itself.

Business relevance

DA serves as a comparative benchmarking tool for evaluating the relative link authority of competing domains. Marketing and SEO teams use it to assess link-building progress, evaluate potential partnership or guest posting targets, and benchmark against competitors. However, DA should not be treated as a direct ranking factor — it is a third-party prediction, not a metric used by search engines in their ranking algorithms.

Implementation example

A B2B company tracking competitive positioning monitors DA alongside organic traffic and keyword rankings for their domain and three key competitors. They use DA trends to evaluate whether their content marketing and digital PR efforts are building link equity at a competitive rate, while recognising that DA alone does not determine search rankings.

Limitations and common misconceptions

Domain Authority is a proprietary Moz metric, not a Google ranking factor. Google has stated it does not use third-party authority scores in its algorithms. DA is best used as a relative comparison tool, not an absolute measure of search potential. Score fluctuations can result from Moz index updates rather than actual changes to a domain's authority. Competing tools (Ahrefs Domain Rating, Majestic Trust Flow) use different methodologies and produce different scores for the same domains.

Topics

Related terms

Sources