Domain Authority

Domain Authority (DA) is a search-engine ranking score created by Moz that predicts how likely an entire domain is to rank well in organic search results, expressed on a scale from 1 to 100. It is not an official Google signal — it is a proprietary estimate derived from Moz's own link index, and its main value lies in comparing your site against direct competitors rather than chasing an absolute number.

How Domain Authority works

Moz crawls the web, builds a link graph and feeds dozens of signals into a machine-learning model that is trained against real search results. The dominant inputs are the number of unique linking root domains, the authority of those linking pages and the overall shape of the site's link profile. Three properties matter when interpreting the score:

• Logarithmic scale — growing from DA 10 to 20 is far easier than from 50 to 60, so progress naturally slows at the top.
• Relative measurement — a DA of 35 can be excellent in a niche market and weak in a competitive one; always benchmark against the sites you actually compete with.
• Recalculation drift — your score can drop even if nothing changed on your site, simply because other domains gained links faster or Moz updated its model.

Comparable metrics from other vendors include Ahrefs' Domain Rating and Majestic's Trust Flow, and each uses a different index, so the numbers are not interchangeable.

Practical applications

SEO teams use DA mainly to qualify link-building prospects: a guest post or mention on a high-authority domain usually passes more value than one on an unknown site. It is also handy for tracking the long-term trend of your own domain after content and outreach campaigns, for pricing expired domains, and for quick competitive snapshots in pitch decks. Because DA can be inflated by spammy backlinks, pair it with quality-oriented signals such as MozTrust, traffic estimates and a manual review before treating any domain as authoritative. Solid technical foundations — fast, reliable hosting and clean site architecture — make it easier to earn the organic links that genuinely raise the score.