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Domain authority is a score of up to 100 points that SEO tools calculate mostly from a site’s backlinks. The best known come from Moz, Ahrefs and Semrush, and Google doesn’t use this score. In the Ahrefs studies on AI, however, brand authority tracks presence in answers more than website authority does.
In short
- DA (Moz), DR (Ahrefs) and Authority Score (Semrush) are relative scores, built mostly from backlinks, and each tool has its own.
- Google says it doesn’t use domain authority and that third-party tools don’t have access to its ranking data.
- In an Ahrefs study of 75,000 brands, DR had a 0.326 correlation with presence in AI Overviews, versus 0.664 for brand mentions.
- On the other hand, SE Ranking found that sites with over 32,000 referring domains were 3.5 times more likely to be cited by ChatGPT than sites with up to 200.
What is domain authority and who calculates this score?
Domain authority is the generic name for scores that estimate website authority from the links a site gets. The three most used are Domain Authority (DA) from Moz, Domain Rating (DR) from Ahrefs and Authority Score from Semrush. All of them are relative. In other words, they compare a site with the others in each tool’s database.
| Score | Who calculates it | What goes into it |
|---|---|---|
| Domain Authority (DA) | Moz | Links, in a machine learning model, from 1 to 100 |
| Domain Rating (DR) | Ahrefs | Strength of the backlink profile, from 0 to 100 |
| Authority Score | Semrush | Links, estimated organic traffic and spam signals, from 1 to 100 |
Moz defines DA as a score that predicts how likely a site is to rank compared to competitors. Even so, Moz itself says DA is not a Google ranking factor and has no effect on search results.
Ahrefs, for its part, says DR shows the strength of a site’s backlink profile compared to the others in its database. So DR can drop even when a site loses no links, because other sites gained links. Ahrefs also advises against judging a site on website authority alone. It suggests checking organic traffic and topic relevance too.
Finally, Semrush calculates the Authority Score from eight factors: link power, estimated organic traffic and six spam signals. For example, one signal is too many referring domains on the same IP address. Semrush advises using the score to compare domains, not as an absolute measure. All three companies sell SEO tools.
How to check the domain authority of a website
To check domain authority, use the tool that calculates the score. At Moz, for example, Link Explorer shows DA with a free community account. In addition, the free MozBar extension shows the score in your browser.
Because each company has its own link database, the DA, DR and Authority Score of the same site don’t match. Therefore, only compare scores from the same tool, and only between sites in the same industry.
Does Google use domain authority to rank sites?
No. Google says it doesn’t use domain authority, a metric from an SEO company. DR and Authority Score are also scores from private companies. Google has its own link analysis systems, such as PageRank. Also, no third-party tool has access to its internal ranking data. So domain authority helps you compare sites, but it doesn’t predict your position on Google.
John Mueller, from Google’s search team, summed this up in a reply on Twitter in 2019. The post was deleted later, but it is still saved in the Internet Archive:
“We don’t use domain authority, that’s a metric from a SEO company.”
John Mueller, Google (2019)
The official documentation agrees. In its guidance on third-party SEO tools, Google says some users misinterpret data from these tools as coming from Google. According to the page, these tools don’t have access to internal ranking data and can’t guarantee performance.
Links, however, still count. In its guide to ranking systems, Google says PageRank is still one of its core systems. In other words, Google looks at links with its own math, not with a tool’s score.
Do AI tools pick sources by website authority or by the page’s answer?
Studies with a published method show that domain authority, calculated from links, has a weak link to brand presence in AI answers. Brand mentions on the web have a much stronger one. One study, however, sees more weight for links in ChatGPT citations. Also, all of them measure correlation, not cause.
Ahrefs matched 75,000 brands against millions of Google AI Overview responses. DR had a 0.326 correlation with brand presence, and the number of backlinks had 0.218. Brand web mentions, by contrast, reached 0.664. But the study only included domains with a DR above 40.
In a second study, from December 2025, Ahrefs added ChatGPT and AI Mode. In ChatGPT, DR had a 0.266 correlation. Ahrefs says ChatGPT seems less influenced by the dominance of established brands. Meanwhile, across the three AI tools, web mentions ranged from 0.66 to 0.71. Both studies measure brand mentions in answers, not cited links. In addition, Ahrefs sells the tool that calculates DR.
When website authority seems to matter more
SE Ranking reached a different result when it analyzed ChatGPT citations across 100,000 prompts, with 129,000 domains in 20 niches. In the company’s model, the number of referring domains was the factor that best predicted citations. Sites with over 32,000 referring domains were 3.5 times more likely to be cited than sites with up to 200.
Even so, .gov and .edu domains had 3.2 citations on average, versus 4 for the others. SE Ranking sells a ChatGPT visibility tool and doesn’t say which country the prompts came from.
One possible reading is that big brands have high website authority and many mentions at the same time. None of the studies separates one effect from the other. Meanwhile, Google’s guide to generative AI says AI Overviews and AI Mode are rooted in Search’s core ranking and quality systems. Therefore, links enter there through SEO, not through a tool’s score.
Why does a smaller site get cited instead of mine?
Because AI cites the page that answers the question, not the site with the highest domain authority. A smaller site with the exact answer, its own data or a clear comparison can beat a portal with a high DR. Also, its brand authority may be higher in the third-party sources AI reads.
The GEO benchmark by researchers from Princeton and other institutions, presented at KDD 2024, tested this. For sites in fifth place in search, citing sources in the text raised their visibility in the generated answer by 115.1%. For the top-ranked site, however, the same method cut visibility by 30.3% on average. According to the authors, the generative engine reads page content, so backlinks should not hurt small creators.
Ahrefs itself, in its December 2025 study, points to ChatGPT as a possible entry point for smaller brands. After all, among the three AI tools, it showed the weakest correlation with almost every classic authority metric.
In practice, then, the diagnosis starts with the question, not the score. Run the questions in your category and see which pages AI cites. Then compare them with yours. Does the answer come first? Is there data, a source and a date? The eight most common causes are in our guide on why AI doesn’t cite your brand.
What builds brand authority beyond backlinks?
Brand authority is how much the web talks about a brand: in articles, videos, forums, reviews and lists, with or without a link. In the Ahrefs studies, this is the signal that tracks presence in AI answers most closely. Unlike domain authority, brand authority doesn’t depend only on links. You build it with content others cite, press coverage and a real presence in communities.
In the December 2025 study, for example, YouTube mentions had the strongest correlation across the three AI tools, at about 0.737. Next came web mentions and link anchors with the brand name. To build brand authority, these paths help:
- Your own data: original research that the press and other sites cite.
- Press: articles earned with data or an expert, which is the work of digital PR.
- Communities and reviews: an identified presence in the sources AI cites most, such as forums and review sites.
- Video: your own content and appearances in third-party videos about your category.
- Topic focus: a blog organized in topic clusters, so the brand is remembered for a subject.
Shortcuts pay off little. According to the same Google guide, in Google Search, seeking inauthentic mentions across the web isn’t as helpful as it seems, because other systems block spam.
On Google, authority is also one of the letters in E-E-A-T, which is about reputation on a topic, not a link score. These paths are part of a content marketing plan for the AI era, from the top to the bottom of the funnel.
How to use domain authority without fooling yourself
Domain authority is still useful as a link gauge, as long as you know what it doesn’t measure. It doesn’t measure brand presence in AI answers or the quality of a page. So use the score next to mention and citation metrics.
- Compare in the same tool: use DA, DR or Authority Score only against competitors in the same industry.
- Judge link partners by topic: besides the score, look at organic traffic and relevance, as Ahrefs itself advises.
- Measure AI separately: run fixed prompts and track your presence and citation rate, as in our protocol for how to measure brand visibility in AI.
- Track mentions: monitor where the brand appears on the web, with or without a link.
- Be wary of promises: according to Google, using a third-party tool or service doesn’t guarantee ranking success.
Next, fix the page before the score. The writing tactics with the most evidence for citations are in our guide on what GEO is.
Frequently asked questions
There is no good domain authority in absolute terms. Ahrefs and Moz say their scores are relative. In other words, a score is good when it is above or close to that of similar sites. For AI, website authority says even less, because brand authority, measured by mentions, shows a stronger correlation with presence in answers.
Buying backlinks is not a safe way for a brand to show up in AI. The Semrush Authority Score, for example, includes six signals of manipulated links, such as too many domains on the same IP address. In addition, Google says seeking inauthentic mentions isn’t as helpful as it seems, because other systems block spam.
Not necessarily. In the SE Ranking study of 129,000 domains, .gov and .edu sites had 3.2 ChatGPT citations on average, versus 4 for other domains. According to the company, what mattered was content quality, not the domain ending.
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Main sources
- Moz, what Domain Authority is and how it is calculated (2025).
- Ahrefs, what Domain Rating is (2026).
- Semrush, what Authority Score is (2026).
- Google Search Central, guidance on third-party SEO tools and advice (2026).
- Ahrefs, AI Overview brand visibility factors, 75,000 brands studied (2025).
- Ahrefs, brand visibility factors in ChatGPT, AI Mode and AI Overviews (2025).
- SE Ranking, study on the factors behind ChatGPT citations (2025).
- Aggarwal et al., GEO: Generative Engine Optimization, KDD (2024).
