What Is Domain Authority? Definition, Scores, and How to Use It

Domain Authority (DA) is a score from 1 to 100, developed by Moz, that estimates how well a website domain is likely to rank in search engine results compared to competitors. It is based primarily on backlink quality and quantity. It is not a Google ranking factor — it is a third-party predictive metric. Most SEO and link-building workflows reference DA to benchmark site strength and qualify link targets.

What Is Domain Authority?

Domain Authority (DA) is a 1-to-100 score developed by Moz that predicts how likely a website is to appear in search engine rankings relative to competing sites. The higher the score, the stronger the site’s estimated ranking potential. DA is calculated using a machine learning algorithm that evaluates backlink data — specifically the number and quality of referring domains pointing to your website domain. Moz updates the score continuously as it recrawls the web. Because DA compares your site against every other indexed domain, the score is relative by nature. A DA of 40 is strong if your competitors average 25, but weak if they average 60. Domain Authority is not a Google ranking factor. Moz’s DA is a third-party metric that Google does not use in its ranking algorithm. The correlation between DA and search engine rankings exists because high-DA sites tend to have strong backlink profiles — and Google does value backlinks. But a high DA score does not cause rankings.

Quick Facts About Domain Authority

DA ranges from 1 to 100; new websites start at DA 1
Moz owns and calculates DA using its own Link Explorer web index
DA is not used by Google to determine search engine rankings
Scores fluctuate as Moz recrawls the web and as other domains gain or lose links
DA is a relative metric — compare your score to competitors in your niche, not to global brands
The only way to improve DA is to earn more high-quality referring domains

Domain Authority vs. Domain Rating vs. Authority Score

Every major SEO platform has built its own version of this metric. Moz calls it Domain Authority, Ahrefs calls it Domain Rating (DR), and Semrush calls it Authority Score. All three measure backlink-based site strength on a 1-to-100 scale, but they use different web indexes and algorithms. Because each tool crawls the web independently, the same website domain authority score will often differ between platforms.

Metric	Creator	Scale	Calculation Basis	Free Checker
Domain Authority (DA)	Moz	1-100	Moz Link Explorer index; referring domains, link quality	Moz Domain Authority Checker
Domain Rating (DR)	Ahrefs	1-100	Ahrefs index; unique referring domains weighted by their own DR	Ahrefs Website Authority Checker
Authority Score	Semrush	1-100	Semrush index; backlinks, organic traffic signals, spam detection	Semrush Authority Score Checker

None of the three is more “correct” than the others. Each reflects the coverage of its own web index. When comparing sites in an outreach campaign, use one metric consistently — mixing DA and DR comparisons in the same analysis produces unreliable results.

Domain Authority vs. Page Authority

Domain Authority (DA) measures the overall strength of an entire website domain. Page Authority (PA), also from Moz, measures the ranking strength of a single page. Both use a 1-to-100 scale and predict ranking likelihood in search engine results pages (SERPs). For most link-building decisions, DA is the right signal. Use DA to evaluate whether a site is worth approaching as a link source. Use PA to evaluate whether the specific page you want a link from is likely to pass strong link equity. A page from a lower-DA domain can have a high PA if it has accumulated many direct inbound links.

How Domain Authority Is Calculated

Moz calculates Domain Authority using a machine learning algorithm built on data from its Link Explorer web index. The algorithm evaluates:

Number of unique referring domains: How many distinct website domains link to the target site
Quality of those referring domains: Links from high-DA sites contribute more than links from low-DA sites
Spam score: Domains with manipulative or toxic backlink patterns may see their DA suppressed
Relative position: DA is normalized across all indexed domains, so score changes elsewhere affect your score even without changes to your backlink profile

Because the score is relative across all indexed domains, it is possible for your DA to drop even if your backlink profile has not changed. This happens when other domains in Moz’s index gain significantly more high-quality links, shifting the relative scale.

What Is a Good Domain Authority Score?

There is no universally good DA score. Domain Authority is a relative metric — what matters is how your score compares to competitors in your specific niche, not against global benchmarks.

Domain Authority score ranges: what a good DA score looks like

DA Range	Typical Profile
1-20	New or very small sites with few referring domains
21-40	Growing sites with a developing backlink profile
41-60	Established sites with solid link presence in their category
61-80	Strong authority sites with extensive backlink profiles
81-100	Major brands, national media, high-authority platforms

A DA of 30 can be highly competitive in a niche where competitors average 20. The same score is weak against competitors averaging DA 55. To set a meaningful target, pull the DA of the 3-5 sites that currently rank for your primary keywords and aim to match or exceed the median. Because DA uses a relative and logarithmic scale, improving from DA 20 to DA 30 is significantly easier than moving from DA 70 to DA 80. Sites like Wikipedia and major news outlets consistently score above DA 90 — those ranges are not realistic targets for most publishers. Focus on your niche benchmark, not on absolute numbers.

Why Domain Authority Matters for Link Building

DA is most useful as a practical signal in your link-building workflow, not as a goal in itself. Here is how practitioners use it day to day.

Benchmarking Your Website Domain Against Competitors

Run a DA check on the top-ranking sites for your target keywords. If your website domain authority score is significantly lower than the sites currently ranking, closing that gap through link building should be a priority. Track your DA monthly as a lagging indicator of campaign progress — meaningful gains typically appear 3 to 6 months after earning new referring domains.

Vetting Link Prospects Before You Pitch

Before spending time on a guest post pitch or outreach email, check the DA of the target website. A common minimum threshold is DA 30 for standard editorial outreach and DA 40-50 for sites where you want maximum link equity transfer. Sites below DA 20 from unknown publishers often have thin organic traffic and low-quality link profiles that pass little value. DA is not the only signal for prospect vetting — organic traffic, topical relevance, and spam score matter too. But it is a fast first filter that prevents wasted outreach effort. Many link-building teams use a DA PA checker or bulk domain tool to screen hundreds of prospects in a single pass before shortlisting outreach targets.

How to Check Your Domain Authority

You can check DA for free using any of these tools:

Moz free Domain Authority checker (free with a Moz account): check any website domain, see DA, PA, and referring domain count
MozBar browser extension: displays DA and PA for every page you visit while browsing
Ahrefs Website Authority Checker (free, no login required): shows Domain Rating, referring domains, and organic traffic estimate
Semrush Authority Score checker (free): shows Authority Score alongside backlink and traffic data

For bulk checks during link-building campaigns, most tools offer a DA PA checker function that lets you paste a list of domains and retrieve scores in one batch. This is the standard approach when screening large outreach lists.

How to Improve Your Domain Authority

7 proven tactics to improve your Domain Authority score

The only lever that directly moves DA is earning more high-quality backlinks from unique referring domains. On-page SEO, content volume, and social media activity do not directly increase DA. Proven tactics to grow your referring domain count:

Create linkable assets: original research, data studies, free tools, and comprehensive guides earn natural citations because other sites reference them
Guest blogging on established sites in your niche: each published piece on a new domain adds a referring domain to your profile
Digital PR: pitch data-led stories to journalists and bloggers; a single media placement from a high-authority outlet adds meaningful link equity
Broken link building: find dead links on relevant pages, create a replacement resource, and notify the site owner to update the link
Link reclamation: find brand mentions without links using Ahrefs or Semrush and ask publishers to add a link
Journalist and media outreach: respond to media queries through services like HARO, Qwoted, or SourceBottle to earn editorial links from news sites
Resource page outreach: get listed on curated link pages in your industry

What does NOT directly move DA:

Writing more blog posts without a corresponding link acquisition strategy
Improving on-page SEO, site speed, or internal linking
Gaining social media followers or social shares
Buying backlinks — this violates Google’s guidelines and can trigger manual penalties

DA is a lagging metric. After earning a meaningful cluster of new referring domains, expect 3 to 6 months before the change is visible in your DA score. Moz recrawls the web on its own schedule, and score updates do not happen in real time.

Domain Authority Limitations and Common Misconceptions

Understanding what DA cannot tell you is as important as knowing how to use it. Common misconceptions about Domain Authority:

DA is not a Google ranking factor: Google does not use Moz’s Domain Authority to rank websites. Moz states explicitly: “Domain Authority is not a Google ranking factor and has no effect on the SERPs.” Google’s John Mueller has confirmed that Google has its own sitewide quality signals that map to similar concepts, but these are distinct from DA.
DA is not the same as PageRank: Google’s PageRank and Moz’s Domain Authority are separate systems from different organizations. PageRank was a Google algorithm; DA is a Moz prediction model.
DA is not a fixed score: DA fluctuates as Moz updates its algorithm, recrawls the web, and indexes new domains. Industry-wide index updates can shift scores across thousands of sites simultaneously, even if your own backlink profile has not changed.
High DA does not guarantee search engine rankings: DA captures backlink strength only. Google’s algorithm also weighs on-page relevance, topical authority, content quality, and user experience signals. A site with DA 60 and thin content can underperform a DA 35 site with deep topical authority.
DA can be artificially inflated: Link farms and private blog networks (PBNs) can temporarily inflate DA. When evaluating domains for outreach, combine DA with organic traffic data and spam score to detect manipulated profiles.

Frequently Asked Questions About Domain Authority

Is Domain Authority the same as Google’s domain authority?

No. Google does not use Moz’s Domain Authority metric. DA is a proprietary score created by Moz to estimate a website’s ranking potential based on its backlink profile. Google has its own internal quality signals, which are separate and not publicly available.

What is a good Domain Authority score?

There is no universal answer. DA is a relative metric — a score of 30 is strong if your competitors average 20, but weak if they average 55. Compare your DA to the sites that currently rank for your target keywords, not to unrelated high-authority sites.

How long does it take to increase Domain Authority?

After earning a meaningful number of new high-quality referring domains, expect 3 to 6 months before the DA score reflects that growth. DA updates lag behind actual link acquisition because Moz recrawls the web on its own schedule.

Does Domain Authority affect my Google rankings?

Not directly. DA is not a Google ranking factor. However, websites with high DA tend to rank well because they have strong backlink profiles, which Google does value. DA correlates with ranking ability — it does not cause it.

What is the difference between Domain Authority and Page Authority?

Domain Authority measures the overall strength of an entire website domain. Page Authority (PA) measures the ranking strength of a single page. Use DA to evaluate a site as a potential link source. Use PA to assess whether a specific page on that site is strong enough to pass meaningful link equity.