Domain authority
Also called: DA, Moz Domain Authority, domain rating, DR, authority score
Definition
Domain Authority is a 1-100 score created by Moz that predicts how likely a website is to rank, based mainly on its links. It is a third-party comparison metric; Google does not use it as a ranking signal.
Domain Authority (DA) is a metric made by Moz, an SEO software company. It scores a website from 1 to 100 to predict how well it might rank compared with other sites. Other tools have their own versions: Ahrefs' Domain Rating (DR) and Semrush's Authority Score are the best known.
None of them is a Google metric.
How it works
Moz says Domain Authority is calculated with a machine learning model that mainly uses link data from its own web index: how many unique domains link to a site (see referring domains), the backlinks behind them, the quality of those links, and other factors that correlate with rankings. Moz describes it as relative: if a huge site gains a billion links, everyone else's DA can drop. The scale is not linear either: Moz notes it is easier to move from 20 to 30 than from 70 to 80. New sites start at 1.
Moz itself is clear on the key point: Domain Authority is not a Google ranking factor and has no effect on search results.
What Google says
Google addressed third-party scores directly in its March 2024 spam policy FAQ: some third-party services provide "reputation" or "authority" scores for sites, and these do not correspond to any of Google's own signals and do not come from Google.
Google does use links (its ranking systems guide says PageRank is still part of core ranking), and it has some site-wide signals. But it does not compute or consult DA, DR or any similar vendor score.
Why it is still useful
DA is a decent shorthand for comparing link strength:
- Benchmarking your site against competitors in the same niche.
- Prospecting, to get a rough sense of a site's link profile before outreach.
- Tracking whether your link profile is growing over time.
Use it as a comparison inside one tool, never as a goal.
How it plays out on Reddit
Reddit has a very high authority score in every tool, which leads some marketers to the wrong conclusion: "post on Reddit to borrow its authority". That is the logic of parasite SEO, and it does not work on Reddit. Promotional posts get removed by mods or Reddit's filters, accounts get banned, and Google's site reputation abuse policy targets third-party content that exists only to exploit a host's rankings.
Reddit threads rank because they contain real questions and real experience, not because of a number in an SEO tool. A thread ranks for "best project tool for a remote design team" because people answered it well. Show up there with a useful answer and you benefit from that ranking honestly. See Reddit SEO.
Common mistakes
- Treating DA as a Google score. Google says these scores do not correspond to its signals.
- Buying links to raise DA. Raising a vendor metric through link schemes violates Google's spam policies and does not help rankings.
- Comparing DA to DR. Different tools, different indexes, different scales.
Frequently asked questions
Does Google use Domain Authority?
No. Domain Authority is a Moz metric. Google has said third-party authority scores do not correspond to its own signals.
What is a good Domain Authority score?
Moz says there is no universal good score; it is relative. Compare your DA with the sites you compete against in search.
What is the difference between DA and DR?
DA is Moz's score and DR is Ahrefs' score. Both estimate link strength on a 100-point scale but use different data and formulas.