8 min read
Domain Authority Score: What It Measures and What Google Uses
Domain Authority is a useful benchmark, but it is a third-party estimate, not a Google ranking factor. Here is what DA, DR and Authority Score actually measure, how to read them and how to build the kind of authority search engines do notice.
A domain authority score is one of the first numbers people look up when judging a website, and one of the most misunderstood. It comes from an SEO tool, not from Google, and it estimates how strong a site's backlink profile is compared with others in that tool's database. Used as a benchmark it is helpful; used as a target in itself it can push a business towards the wrong work.
What is Domain Authority?
Domain Authority (DA) is a score from 1 to 100 developed by Moz. It predicts how likely a site is to rank compared with competing sites, based mainly on backlink data from Moz's own link index.
Moz calculates DA with a machine-learning model that weighs factors such as the number of linking root domains and the quality of those links. Moz describes the scale as relative: when very large sites gain links, other sites' scores can shift. It also notes that climbing from 20 to 30 is easier than from 70 to 80. New websites start at 1.
The term is often used loosely for any "authority" metric, but Domain Authority is Moz's trademarked score. Other tools publish their own equivalents under different names.
Does Google use domain authority?
No. Google does not use Moz Domain Authority or any other third-party authority score. Moz itself states that DA is not a Google ranking factor and has no effect on search results.
That does not mean links or site-level reputation are irrelevant. Google's guide to its ranking systems says that link analysis, including an evolved form of PageRank, is still part of its core ranking systems. It also says that ranking works mainly at page level, while site-wide signals and classifiers contribute too.
So when people talk about "Google domain authority", they usually mean these internal signals. Google does not publish them as a score, and third-party metrics only approximate part of the picture, using their own crawl of the web.
Domain Authority vs Domain Rating vs Authority Score
The three best-known authority metrics come from Moz, Ahrefs and Semrush. All are third-party estimates built on each tool's own index, so the same site gets different numbers in different tools.
| Metric | Provider | Level | Main inputs |
|---|---|---|---|
| Domain Authority (DA) | Moz | Whole domain, 1 to 100 | Machine-learning model on link data, including linking root domains and link quality |
| Page Authority (PA) | Moz | Single page, 1 to 100 | The same approach applied to an individual URL |
| Domain Rating (DR) | Ahrefs | Whole domain, 0 to 100 | Strength of the backlink profile; each linking domain splits its rating among the domains it links to |
| Authority Score (AS) | Semrush | Domain or page | Link power, estimated organic traffic and spam indicators in the link profile |
Page Authority and Domain Authority are calculated separately: a strong page can sit on a modest domain and the other way round. Ahrefs explains that a domain linking to millions of sites passes less to each of them than a smaller domain with few outbound links, so a link from a small, selective site can count for more than one from a site that links everywhere. Semrush adds traffic and spam checks so that Authority Score is harder to inflate with links alone.
How to check your domain authority
To see your domain authority score, enter your domain in Moz Link Explorer, the free Moz domain checker or the MozBar extension. Ahrefs and Semrush show their own metrics in their domain overview reports.
Whichever tool you choose, the method matters more than the number:
- Pick one primary metric and stick to it; scores from different tools are not comparable.
- Record it monthly rather than daily, because index updates cause noise.
- Check the same metric for the sites that rank for your most important queries.
- Look beneath the score at referring domains: which sites link to you, and are they relevant?
Many free "domain SEO score" checkers simply display one of these third-party metrics, sometimes mixed with basic on-page checks. Published lists of DA rankings are just as tool-specific: they show how sites compare inside one index, not how Google ranks them.
What is a good domain authority score?
There is no universally good score. A good domain authority score is one that is comparable to or higher than the sites competing for the same queries in your niche and market.
Imagine a local plumber with a DA in the 20s: it may still outrank national directories for "emergency plumber" in its town, because relevance and location matter for that query. A news publisher, by contrast, competes with sites holding scores in the 90s. Both Moz and Ahrefs advise judging their metrics relative to competitors rather than in absolute terms.
The trend is more informative than any single value. A steady rise alongside more relevant referring domains suggests that promotion is working; a sudden jump with no visible new links usually means the tool updated its index.
How to improve domain authority the sustainable way
The only durable way to improve domain authority, and to increase Ahrefs Domain Rating, is to earn links from relevant, reputable sites. Everything that makes your site worth citing supports that goal.
Create content that others want to cite
Original data, useful tools, clear explanations of complex rules and honest comparisons attract links over time. A survey of customers in your sector or a calculator people bookmark gives other sites a reason to reference you.
Earn links through real relationships
Suppliers, partners, industry associations, local press and event organisers often link to businesses they genuinely work with. Expert commentary for journalists and talks at events build links that also bring visitors.
Fix the technical foundations
Links help only if they reach working, indexable pages. Redirect old URLs that still attract links, repair broken internal links and make sure important pages are not blocked or orphaned. These are core technical SEO tasks, and they decide whether earned links count at all. Internal linking and topic clusters then pass value from linked pages to the rest of the site.
Use authority metrics to choose link prospects
Authority scores are most useful when deciding where to spend outreach effort. A relevant trade publication with a modest score is often a better prospect than an unrelated authority website with a high one, because the link makes sense to readers and is more likely to send visitors who care.
Be careful with "toxic link" clean-ups
Many tools flag toxic backlinks, but Google's own guidance says most sites never need the disavow tool. It is meant for sites with a considerable number of spammy, artificial or low-quality links that have caused, or are likely to cause, a manual action.
Buying links, private blog networks and large-scale link exchanges may push a third-party score up for a while, but they break Google's spam policies and put real visibility at risk. Treat them only as something to avoid.
What domain authority cannot tell you
Domain authority measures links as one tool sees them. It says nothing about content quality, relevance, search intent or whether a page actually ranks, so it should never be your main measure of SEO success.
- It can be inflated. Manipulative links can raise a score without improving visibility.
- It ignores relevance. A link from an unrelated high-DA site counts towards the score but may do little for your rankings.
- It reflects one index. Changes in a tool's crawl can move the number when nothing changed on your site.
- It is a vanity metric when used alone. Clicks, rankings for target queries and enquiries from organic search show results; DA only hints at potential.
To see how your link profile compares with competitors and what is actually holding the site back, start with a QIO SEO audit.
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Questions and answers
Is domain authority a Google ranking factor?
No. Domain Authority is a Moz metric, and Moz itself says it has no effect on Google results. Google uses its own internal signals, including link analysis, and does not publish them as a score.
Why is my DA different from my DR?
Moz and Ahrefs use different link indexes and different formulas. The two numbers measure similar things in different ways and should not be compared directly.
How long does it take to raise domain authority?
It depends on how quickly you earn relevant links and on how often the tool refreshes its index. Treat it as a slow-moving indicator rather than something to change in weeks.
Is domain authority still relevant?
It is still useful for comparing link strength with competitors and for qualifying link prospects. It is not useful as a goal in itself.
Can I buy a higher domain authority?
Services selling score increases rely on link schemes that break Google's spam policies. The score may rise while real search visibility is put at risk.
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