Moz's proprietary score (1-100) predicting how well a website will rank, based on link profile and other factors.
Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how likely a website is to rank highly in search engine results pages. Scored on a scale from 1 to 100, with higher scores indicating greater ranking potential, DA is calculated using multiple ranking factors including the quantity and quality of external backlinks pointing to a domain.
Unlike Google's internal metrics, Domain Authority is a third-party metric designed to approximate a site's overall SEO strength. It serves as a comparative tool for evaluating websites against competitors rather than an absolute measure of ranking success. The logarithmic scale means moving from 20 to 30 is easier than jumping from 70 to 80, reflecting the increasing difficulty of building authority at higher levels.
Why It Matters for AI SEO
In the era of AI-powered search, Domain Authority remains relevant but must be interpreted alongside newer signals that AI systems prioritize. Google's algorithms increasingly focus on expertise, authoritativeness, and trustworthiness (E-A-T), which correlate with but don't perfectly match traditional DA metrics. AI systems also evaluate content quality, user engagement, and topical authority more sophisticatedly than earlier algorithms. Modern SEO practitioners use DA as part of a broader authority assessment that includes domain age, content quality signals, and brand recognition factors that AI systems can better understand. While a high DA doesn't guarantee rankings in AI-influenced SERPs, it often indicates the foundational link equity and trust signals that support content visibility.
How It Works
Domain Authority is calculated using a machine learning model that evaluates over 40 factors, with the most important being the root domain's backlink profile. The algorithm considers linking domain diversity, link quality, and the authority of linking sites. Tools like Moz Pro display DA prominently in their dashboards, while competing platforms like Ahrefs offer Domain Rating (DR) and Semrush provides Authority Score as alternative metrics. Practical application involves using DA for competitive analysis and link building prioritization. SEO practitioners compare their site's DA against competitors to understand the link building gap, prioritize outreach to higher-authority domains, and set realistic ranking expectations. When evaluating potential link opportunities, targeting domains with DA scores 20+ points higher than your own typically provides the most value.
Common Mistakes
The most significant mistake is treating Domain Authority as a direct ranking factor rather than a correlation metric. Google doesn't use Moz's DA in its algorithms, so optimizing specifically to increase DA without considering actual ranking factors wastes effort. Many practitioners also misunderstand that DA is relative—a score of 50 today might drop to 45 tomorrow if competitors improve faster, even without losing actual authority. Another common error is focusing solely on DA while ignoring relevance and topical authority. A high-DA link from an unrelated industry often provides less SEO value than a moderate-DA link from a topically relevant, authoritative source within your niche.