Domain Authority
Domain Authority (DA) is a predictive score from 1 to 100, created by Moz, that estimates how likely a given domain is to rank well in search results. It is not an official Google ranking metric but a relative estimate produced by a third-party SEO company from its own data.
- Domain Authority (DA) is a 1-to-100 predictive score built by Moz that estimates a domain's likelihood of ranking in search.
- It is not an official Google ranking signal, and Google has stated repeatedly that it does not use DA for crawling, indexing, or ranking.
- The score runs on a logarithmic scale, so climbing from 70 to 80 is far harder than climbing from 20 to 30.
- It works best as a relative comparison between competing domains rather than as an absolute benchmark.
- DA is a distinct metric from Ahrefs' Domain Rating (DR) and from the broader notion of website authority.
Overview
Domain Authority is a metric developed by the SEO tool vendor Moz that predicts, on a scale of 1 to 100, how likely a domain is to rank highly on search engine results pages (SERPs). A higher score signals a greater likelihood of ranking. Brand-new sites typically start around 1 and see their score rise as they accumulate authoritative inbound links.
The key point is that Domain Authority is not a value assigned by search engines themselves. It is an estimate Moz produces from its own web index and model. Because of this, the same site can receive a different authority score depending on which tool measures it.
How the Score Is Calculated and the Logarithmic Scale
Moz calculates Domain Authority with a machine learning model that combines more than 40 signals, including the number of linking root domains and the total number of links pointing to the domain. Backlink quantity and quality serve as core inputs, so a domain that earns many links from authoritative sites tends to score higher.
Domain Authority is designed on a logarithmic scale, which means the difficulty of raising the score varies sharply across its range. Moving from 20 to 30, for example, is much easier than moving from 70 to 80, because each additional point at the high end demands an exponentially larger volume of quality links.
| Score Range | Typical Interpretation |
|---|---|
| 1-20 | New or small domains; fresh sites usually start near 1 |
| 20-40 | A mid-range tier reachable through steady, ongoing operation |
| 40-60 | Domains that have consistently built up quality links |
| 60-80 and above | Domains with years of accumulated authoritative links; gains grow dramatically harder at the top end |
Not a Google Ranking Factor
The most common misconception about Domain Authority is that the score directly influences Google search rankings. Google has clearly denied this. In 2019, Google's John Mueller stated, "We don't use DA. We use a lot of factors, but I wouldn't call them 'DA'", and he has repeatedly noted that Domain Authority is a metric made by an SEO company, not by Google. Gary Illyes of Google made a similar point in 2017, saying "We don't use Moz's DA metric in our algorithm".
In short, raising your Domain Authority score does not, by itself, cause your Google rankings to improve. Domain Authority is an external approximation of Google's algorithm, while actual rankings are determined by the many proprietary signals Google uses internally.
Practical Use
Domain Authority is meaningful when used as a tool for relative comparison rather than as an absolute performance metric. It is well suited to tasks such as:
- Comparing your domain's authority against competing domains on a common scale
- Tracking your domain's authority over time to gauge whether your link strategy is moving in the right direction
- Assessing the relative strength of candidate sites for links or partnerships
By contrast, treating Domain Authority as a single KPI or chasing the score for its own sake is not advisable. Low-quality links acquired to inflate the number can raise risk rather than reward, and the score is not a value Google itself looks at.
Distinction from Similar Metrics
Several metrics look similar to Domain Authority but are distinct, and it is important not to confuse them.
- Domain Rating (DR) is a separate metric produced by Ahrefs that primarily expresses the strength of a backlink profile on a 0-to-100 scale. Its source and calculation method differ from Moz's Domain Authority.
- Website authority is not a specific score but a broad concept describing a site's trustworthiness and expertise. It operates at a different level than the specific Domain Authority number.
In other words, Domain Authority is a narrow term referring to "a specific 1-to-100 score created by Moz," and it should be used distinctly from DR and from the general idea of authority.