SEO Learning Center · Link Building
What Is Domain Authority?
Domain Authority (DA) is a third-party metric that predicts how likely a website is to rank in search engine results, based on a 1-to-100 scale. It was developed by Moz, an SEO software company, and has become one of the most widely referenced metrics in the SEO industry.
Off-Page SEO
Not a Google Ranking Factor
Backlink Metric
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It's important to understand from the start: Domain Authority is not a Google ranking factor. Google does not use DA in any way when deciding how to rank websites. Instead, DA is Moz's own estimate, built from data Moz collects, and it's meant to help SEOs compare websites and track progress over time.
Domain Authority is also a comparative metric, meaning a score is only meaningful when measured against similar websites. A DA of 30 might be strong for a small local business site but weak for a national publication, so context always matters more than the number itself.
How Domain Authority Is Calculated
Moz calculates Domain Authority using machine learning. The model looks at dozens of factors from Moz's Link Explorer index and finds correlations with how well sites tend to rank in Google's search results. Some of the core inputs include:
- Linking root domains — the number of unique websites linking to a domain
- Total number of links — including both the quantity and variety of links pointing to a site
- Link quality — links from authoritative, trustworthy sites carry more weight than links from low-quality or spammy sites
The output is a single score from 1 to 100. Higher scores indicate a stronger predicted ability to rank, though the scale itself is logarithmic. This means it becomes progressively harder to gain points as a score increases. Moving from 20 to 30 is far easier than moving from 70 to 80.
Because DA is a relative, comparative metric, scores are most useful when measured against similar websites, not viewed as an absolute number on their own.
New websites typically start with a low Domain Authority, since they haven't yet had time to earn established backlinks. This is normal and expected, not a sign of a problem.
Domain Authority vs. Page Authority
Domain Authority and Page Authority (PA) are related but measure different things:
| Metric | What It Measures |
|---|---|
| Domain Authority | The overall ranking strength of an entire domain |
| Page Authority | The ranking strength of a single specific page |
A website can have a high Domain Authority overall while individual pages on that site have varying Page Authority scores, depending on how many quality links point directly to each page.
Why Domain Authority Matters for SEO
Even though Google doesn't use DA directly, the metric still holds practical value for a few reasons:
Benchmarking against competitors
DA gives SEOs a quick way to compare the relative strength of one website against another in the same niche.
Tracking progress over time
As a site earns more high-quality backlinks and builds authority, its DA score typically trends upward, offering a rough indicator of link-building progress.
Evaluating link opportunities
When considering where to seek backlinks or guest posting opportunities, many SEOs use DA as one signal (among several) to judge whether a site is a credible, worthwhile source of a link.
Communicating value to stakeholders
DA offers a simple, easy-to-explain number that non-technical stakeholders or clients can understand when discussing off-page SEO progress.
Common Misconceptions About Domain Authority
Myth
"Higher DA guarantees higher rankings."
This is false. DA is a prediction based on link data alone. Google's actual ranking systems weigh hundreds of factors, including content relevance, search intent, user experience, and technical SEO, none of which DA accounts for.
Myth
"DA is a Google metric."
DA is proprietary to Moz. Google has publicly stated it does not use Domain Authority, or any third-party authority score, as a ranking signal.
Myth
"A low DA means a site can't rank."
Newer or smaller websites can and do rank well for less competitive keywords even with a modest DA score, particularly when their content closely matches search intent.
Myth
"DA scores are directly comparable across all tools."
Other platforms offer similar metrics with different names and different calculation methods, such as Ahrefs' Domain Rating (DR) or Semrush's Authority Score. These numbers are not interchangeable, since each tool uses its own index and algorithm.
Factors That Influence Domain Authority
While the exact algorithm is proprietary, DA is primarily influenced by a site's backlink profile. Key contributing factors include:
- Number of referring domains: More unique domains linking in generally strengthens a score
- Authority of linking domains: Links from high-authority, trusted sites carry more weight
- Link diversity: A natural mix of link types and sources looks more credible than links from a single pattern or source
- Spam signals: Toxic or manipulative link patterns can suppress a score
- Historical link growth: Consistent, natural growth over time tends to support a stronger score
Domain Authority is primarily based on Moz's analysis of a site's backlink profile. While content quality, on-page SEO, and technical SEO are important for overall search performance, they are not direct inputs into the DA calculation itself.
How to Check Domain Authority
Domain Authority can be checked using Moz's free tools, including the MozBar browser extension or Moz's Link Explorer. Simply enter a domain to see its current DA score, along with related metrics like linking root domains and spam score.
How to Improve Domain Authority
Since DA is driven almost entirely by backlinks, improving it comes down to consistent, ethical link building:
- Earn links from relevant, authoritative sites through quality content that naturally attracts citations
- Avoid spammy link schemes, such as buying links or joining link farms, which can hurt a score and risk search engine penalties — see our white hat vs. black hat SEO guide for what to avoid
- Diversify link sources rather than relying on a single website or type of backlink
- Fix or disavow toxic backlinks that may be dragging the score down
- Be patient — Domain Authority is recalculated each time Moz updates its link index, so score changes may lag behind actual improvements to a site's backlink profile
Domain Authority and Real SEO Strategy
Domain Authority is best treated as a diagnostic and benchmarking tool, not a goal in itself. Chasing a higher DA number without a broader strategy can lead to wasted effort, such as pursuing low-value backlinks purely to move the metric. A more effective approach treats DA as one data point among many, alongside organic traffic, keyword rankings, and conversion metrics, when evaluating overall SEO health.
FAQ
Can a website rank with low Domain Authority?
Yes. A website with a low Domain Authority can still rank well if its content is highly relevant, satisfies search intent, and faces limited competition. DA is a comparative metric, not a ranking guarantee.
Summary
Domain Authority is a third-party score developed by Moz that estimates a website's likelihood of ranking well in search results, based primarily on its backlink profile. It is not used by Google as a ranking factor, but it remains a useful benchmarking and tracking tool within the SEO industry. Understanding what DA measures, and just as importantly what it doesn't measure, helps SEOs use it appropriately alongside other performance metrics rather than treating it as a direct predictor of search success.
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