Domain authority: a complete guide

If you have ever asked an SEO specialist why a competitor ranks above you on Google, you have probably heard: "They have a higher domain authority." It sounds like a verdict, as if Google had given their site a number and yours is smaller. The truth is more interesting. The number is not Google's, several companies calculate it in different ways, and yet it still says something true about how search works.

This is the long guide. If you only need the short version (what it is, how to check your site and which links help), start with what domain authority is and how to raise it. Here we go deeper: where the idea came from, how each score is calculated, what Google says, how to compare yourself with competitors step by step, 15 ways to earn real links, and which "quick" routes end in trouble. Sources are listed at the end.

In short

• Domain authority is the umbrella name for scores that predict how "strong" a site is in search, mostly from the links pointing to it. The best known are Domain Authority (Moz), Domain Rating (Ahrefs), Authority Score (Semrush) and Trust Flow (Majestic).
• Google uses none of them [1][8]. But Google does use the links they are based on [6].
• The scale is logarithmic: going from 10 to 20 is much easier than going from 60 to 70.
• There is no good number. There is only better or worse than the sites you compete with for the same search.
• It grows slowly, and only when someone has a real reason to recommend you. Bought links are explicitly against Google's rules [12].

Where the idea came from: from PageRank to DA

In 1998 two Stanford PhD students, Sergey Brin and Larry Page, published a paper about a new search engine. Their core idea was simple: a link from one page to another is like a vote. A page that many pages link to is probably important, and a vote from an important page counts for more than a vote from an obscure one. They called the score PageRank and built Google on it [5].

For years Google showed a rough version of PageRank in public: the Google Toolbar gave every page a score from 0 to 10. Site owners watched it like a stock index, and link sellers sold "a link from a PR6 site". Google stopped updating the public score in 2013 and removed it completely in 2016 [7]. Internally, PageRank stayed: in its official list of ranking systems, Google says the way it works "has evolved a lot" and that it "continues to be part of our core ranking systems" [6].

When the public number disappeared, SEO companies filled the gap. They crawl the web with their own robots, collect billions of links and calculate their own scores to stand in for the missing PageRank. That is how Moz's Domain Authority, Ahrefs' Domain Rating and the others came about. All of them try to answer the same question from the outside: how much trust does this site have, judging by the links to it?

The four best-known scores

Domain Authority (Moz)

Moz calculates Domain Authority with a machine-learning model that mostly looks at link data [1]. The model is trained to predict which sites will rank higher in Google, and then gives each site a score from 1 to 100. In March 2019 Moz released a major change (Domain Authority 2.0) that added new signals, including signs of spam in the link profile. Moz itself says it plainly: Domain Authority is not a Google ranking factor and has no effect on the results [1].

An important consequence: DA is a comparative score. If Moz updates its model or its index, your number can drop without you losing a single link, simply because other sites grew more.

Domain Rating (Ahrefs)

Ahrefs calculates Domain Rating in a way similar to PageRank, but between whole websites rather than individual pages [2][3]. It counts the unique domains linking to you with at least one followed (dofollow) link, and each of them passes on as much as it is worth itself, divided by the number of sites it links to.

Ahrefs gives a good example: a DR 10 site that links to only three sites can help you more than a DR 80 site that links to a million [2]. A link's strength is "split" among everything it points to. That is why a link from a small but selective local site is sometimes worth more than a link from a huge directory.

One more thing that surprises people: a hundred links from the same site count almost like one. For DR, what matters is how many different sites recommend you.

Authority Score (Semrush)

Semrush combines three things into a score from 0 to 100: link power (how many followed domains link to you and how strong they are), organic traffic (how many visits you are likely to get from Google based on your rankings) and how "natural" the profile looks, meaning signs that the links are artificial [4]. An example of such a sign: lots of links but almost no traffic, or dozens of "different" sites on the same server. Semrush also stresses that its score is not a ranking factor and that a "good" number depends entirely on your competitors [4].

Trust Flow and Citation Flow (Majestic)

Majestic splits the idea in two. Citation Flow measures how much "power" the links carry, in other words their volume. Trust Flow starts from a hand-picked list of trustworthy sites and measures how close you are to them along the chain of links [9]. If Citation Flow is much higher than Trust Flow, that often means a lot of low-quality links.

Why one site has four different numbers

Check the same site everywhere and you will get different numbers. A made-up but typical example for a local car service:

None of this is a mistake. Each company has its own crawler that finds a different part of the web, its own formula and its own scale. So never compare one site's DA with another site's DR. Pick one tool and compare everyone in it.

Does Google use domain authority?

Short answer: no, not these numbers. Google's John Mueller has said so many times, most clearly like this: Google doesn't use Domain Authority "at all" when it comes to crawling, indexing or ranking [8].

Longer answer: Google doesn't use someone else's score, but it has its own ways of judging how much trust a site deserves. Three things are certain:

1. Links are a signal. As we saw, Google itself lists PageRank and its link analysis systems among its core systems [6].
2. Google measures at site level, not only at page level. In May 2024, internal Google Search documentation leaked and was analysed publicly by Rand Fishkin (SparkToro) and Mike King (iPullRank). Among the thousands of fields in it is one called siteAuthority [10]. What exactly it measures and how much it weighs is unknown; Google warned that the documents were out of context and incomplete. But it is reasonable to assume that some kind of "whole-site authority" signal exists, just not Moz's number.
3. Content and trust carry their own weight. Google describes quality in terms of experience, expertise, authoritativeness and trustworthiness (E-E-A-T) [16]. That is not one number but a set of signals: who is behind the site, whether others cite it, whether the text is useful.

So the best way to think of DA and DR is as a thermometer. A thermometer doesn't cure anything, but if yours reads 34 and a competitor's reads 38, you know where to look.

Why a higher DA doesn't always win

If domain authority decided everything, Wikipedia would rank first for every search. It doesn't, and the reasons are useful for a small business:

• Topic beats strength. A huge news site has no page for "brake pad replacement Plovdiv". You do. Google looks for the best answer to that specific search, not the strongest site on the internet.
• Local searches play by their own rules. For "hairdresser Varna" or "locksmith near me", the map and Google profiles take up much of the screen. What counts there is proximity, reviews and how complete the profile is. More: Google Business Profile step by step and how to get more Google reviews.
• Strength sits on the page, not only on the domain. A link points to a specific page. If every link goes to your homepage while your service pages are three clicks deep with nothing pointing to them, they get little of that strength. This is where internal links help.
• Competition differs from search to search. For a rare search, a page with no external links at all can rank first. Ahrefs' large 2023 study found that 96.55% of the pages in its index get no traffic from Google, but also that plenty of pages without links still get traffic, almost always on low-competition topics [17].

Still, for competitive searches, links matter. A Backlinko analysis of 11.8 million Google results found that the first result has on average 3.8 times more backlinks than positions 2–10 [18]. That is a correlation, not proven cause, but the direction is clear.

What is a "good" number?

There is no universally good number. Here are rough ranges in Ahrefs DR, just to give a sense of scale:

What matters is not which box you are in but who you compare yourself with. If the top five sites for "car service Plovdiv" are between 8 and 15 and you are at 3, the gap is within reach. If you are up against national directories at 60+, it is smarter to compete for narrower searches ("automatic gearbox repair Plovdiv") and for the map.

How to compare your site with competitors, step by step

This is a half-hour exercise that tells you more than any number on its own.

1. Pick 3–5 searches that bring customers. For example "car service Plovdiv", "timing belt replacement Plovdiv", "car diagnostics Plovdiv". How to find them: keyword research for a small business.
2. Search for them on Google in an incognito window and note the top 5 regular results (skip the ads, and the directories unless they are direct competitors).
3. Check each one in a single tool, for example the free Ahrefs Website Authority Checker. Note the DR and the number of domains linking to it.
4. Make a table. It might look like this (made-up numbers):

5. See where their links come from. The free Ahrefs Backlink Checker shows the strongest links to each site. You will almost always see the same kinds of sources: suppliers, a trade association, local media, a council website, a sponsorship.
6. Mark the ones you could get too. If the parts supplier links to three garages and you also work with them, you have your first task.

That is the real value of domain authority: not the number itself, but the map of who recommends your competitors.

How to check your own site

Besides the tools above, there is a free source straight from Google: Google Search Console. Its Links report shows which sites link to you, to which of your pages and with what text [15]. That is Google's own data, not a third-party estimate. If you don't have Search Console yet, here is how to set it up.

Useful free tools:

• Ahrefs Website Authority Checker: DR and number of domains.
• Ahrefs Backlink Checker: the strongest links to any site.
• Moz Link Explorer: Domain Authority, with a free account.
• Semrush Website Authority Checker: Authority Score.

Write your numbers in a dated table. Check again with the same tool in three months.

Anatomy of a good link

Not all links are equal. Here is what makes a link valuable, in order of importance:

1. A related topic. A link from a tyre supplier to a car service makes sense. A link from a cooking blog to a car service is odd, for people and for Google.
2. A real, respected site. It has its own visitors, writes about real things, and others cite it too.
3. A link in the text, placed for a reason. "We had the air conditioning fixed by [Service X]" in an article is worth far more than a line in a list of 300 companies in a page footer.
4. A new domain, not another link from the same one. Ten different sites with one link each beat one site with ten links.
5. Natural link text. The words you click on help Google understand what the page is about. But if 30 sites link to you with exactly "cheap car service Plovdiv", it looks staged. A natural mix is the company name, the web address, "here", and sometimes the service.
6. A page someone reads. A link from a page with real visitors can bring you customers, not just strength.

Link attributes: follow, nofollow, sponsored, ugc

Every link can carry a label that tells Google how to treat it [11]:

Until 2019, nofollow meant "ignore". Since then Google treats it as a hint and introduced sponsored and ugc [11]. Links from Facebook, Instagram, Wikipedia and most forums and listings carry such attributes. They are still useful: they bring visitors and make your presence look natural. Just don't expect them to raise your DR.

How to check a link yourself: right-click it → Inspect, and look for rel="nofollow", "sponsored" or "ugc" in the code.

15 ways to earn real links

All of these have one thing in common: they give someone a reason to mention you. Start with the first few, they are the easiest.

1. Partners and suppliers. Many companies have a "Partners" or "Where to find us" page. A fireplace maker links to installers, a tile supplier to tradespeople. Ask.
2. Business clients. If you built something for another company, ask for a "Contractor: …" line with a link. Builders and designers do this all the time.
3. Trade bodies and chambers. Membership of a trade association or a chamber of commerce (in Bulgaria, the Bulgarian Chamber of Commerce and Industry) often comes with a directory profile.
4. Local media with a story. A new service, ten years since opening, an interesting project, a donation. Regional news sites such as sofianews.bg or burgasnews.bg look for local stories every day. Send a short text and photos, not a sales brochure.
5. Expert comment. Journalists write seasonal pieces: "how to get your car ready for winter", "what to check before a bathroom renovation". Offer yourself as the local specialist who answers quickly.
6. Your own data. "What a bathroom renovation costs in Sofia in 2026: prices from 120 of our jobs." Media and blogs love to cite something like that, because nobody else has it.
7. Useful guides and calculators. A tile calculator, a service interval table, a guide to "what to do after a road accident". People link to useful things on their own.
8. A review of a supplier. Write an honest review of software, a machine or a material you use. Many companies publish customer reviews with the customer's name and site.
9. Local sponsorships. A children's team, a neighbourhood festival, a charity run. Your name goes on their site. If the link is there because you paid, it should be marked sponsored; the benefit is trust and visibility, not strength.
10. Events and training. A free seminar at a community centre, a talk at a vocational school, an open day. Events get announced on websites, and the announcements stay.
11. Unlinked mentions. Search for your company name on Google in quotes. If someone wrote about you without a link, politely ask them to add one. It is the easiest link of all, because they already like you.
12. Broken links. If a trade site links to a company that no longer exists, tell them and suggest your page as a replacement.
13. Photos. Good photos of your jobs or products that you allow others to use in exchange for a credit link.
14. A guest article you would read without the link. A trade blog or local site may publish a useful piece of yours. Write for their readers, not for the link; mass "guest posts" made only for links are a scheme in Google's eyes [12].
15. Pages for your projects. A separate page for each big project gives the client, the supplier or the media something specific to link to. More: why separate case study pages help SEO.

Directories, social media and your Google profile don't raise DR much, but they are the foundation every new site should have in its first weeks. That is covered in new website? how to help it climb in Google faster.

What to avoid: shortcuts that end up costing you

Google spells out which practices it considers "link schemes" and spam [12]. Here are the most common ones a small business meets in the form of an "offer":

• Bought links that pass strength. "50 links from DA 40+ sites for €100." Buying and selling links for ranking is explicitly in the rules [12].
• Site networks (PBNs). Dozens of sites built only to link to each other or to someone's clients. They look real until you look closely.
• Mass link swaps. "I'll link to you, you link to me" with dozens of strangers.
• Automated links. Software that drops comments and profiles across forums.
• Old domains bought for their "strength". Some people buy an expired domain with a high DR and put something completely different on it, hoping to inherit its trust. Since March 2024 Google has a separate policy against this: expired domain abuse [13].
• Renting someone else's reputation. Articles placed on strong sites only to rank, without the site itself being genuinely involved. That too has had its own policy since 2024 (site reputation abuse) [13].

If someone promises you "DA 50 in a month", they are selling the number, not the result. DA and DR are easy to inflate with low-quality links, and Google simply ignores or penalises them.

What happens if it happens anyway

In 2012 Google launched the Penguin algorithm against artificial links, and many sites lost their rankings within days. Since 2016 Penguin runs continuously and tends to devalue spam links rather than penalise the whole site [19]. In other words, bought links most often just don't help and the money is gone. For blatant schemes, Google can also apply a manual action, which shows up in Search Console.

And if you see hundreds of strange links to your site that you never ordered? Don't panic. Google says most sites do not need the Disavow tool, and that it is only for cases where you have many artificial links and a manual action, or are sure one is coming [14].

Domain authority myths

1. "Google gave me DA 12." No. Moz gave you DA 12. Google publishes no such number [1][8].
2. "Higher DA always ranks higher." Only if everything else is equal, and it never is. Topic, page and location often decide more.
3. "Nofollow links are worthless." They bring visitors, make the profile natural, and since 2019 Google may take them into account as a hint [11].
4. "The more links, the better." A hundred links from one directory weigh less than three links from different related sites.
5. "A new domain has no chance." A new site starts from zero, but for local and narrow searches it can reach page one within a few months. More: how long SEO takes.
6. "If I buy an old domain, I inherit its strength." If the topic is the same and the business is a genuine continuation, that's possible; if not, it is exactly the practice Google has a policy against [13].
7. "My DA dropped, so I've been penalised." Most often the tool updated its index or formula, or competitors grew. Check Search Console for manual actions before you worry.

Don't lose the authority you already have

The easiest link is the one you already have. The most common way to lose it is a new site or changed addresses. If the old page site.com/services.html becomes site.com/services and nobody sets up a redirect, every link to the old page leads to a 404 error and its strength is lost.

Google recommends permanent (301) redirects from every old address to its new equivalent [20]. Before launching a new site, pull a list of the pages that external links point to (from Search Console or Ahrefs) and check that each one has somewhere to go. More on moving: how to move your domain to a new website.

How long it takes

Links build up slowly, and both the tools and Google discover them weeks late. A realistic picture for a local business starting from zero and doing something every month:

This is a guide, not a promise: it depends on the industry, the city and the competition.

How to track progress

Once a month, in one table:

• DR or DA from the same tool.
• Number of domains linking to you.
• New links from Search Console's Links report.
• Rankings for 3–5 main searches.
• Enquiries and calls from the site. This is the only number that actually pays the bills. How to measure it: how to measure what your website brings you.

If DR grows but enquiries don't, the problem is the pages, not the links. If enquiries grow while DR stands still, don't worry at all.

Glossary

• Backlink: a link from another site to yours.
• Referring domain: a separate site that has at least one link to you. Matters more than the number of links.
• Anchor text: the words you click on.
• Follow / nofollow: whether a link is a recommendation that passes strength or only a hint.
• PBN (private blog network): a network of sites built only for links. Not allowed.
• Disavow: a Google tool for rejecting links. You will almost never need it.
• Page Authority / URL Rating: the same idea, but for a single page rather than the whole site.
• E-E-A-T: experience, expertise, authoritativeness and trustworthiness, the way Google describes quality content.

See also

• What domain authority is and how to raise it: the short version of this guide
• New website? How to help it climb in Google faster
• Internal linking and SEO
• SEO for a business website: where to start
• Local SEO checklist
• Web design: a complete guide

References

1. Moz. "What is Domain Authority?" moz.com/learn/seo/domain-authority
2. Ahrefs Help Center. "What is Domain Rating (DR)?" help.ahrefs.com
3. Ahrefs Blog. "Domain Rating: What It Is & What It’s Good For." ahrefs.com/blog/domain-rating
4. Semrush Knowledge Base. "Authority Score." semrush.com/kb/747-authority-score
5. Wikipedia. "PageRank" (with links to Brin and Page's original 1998 paper). en.wikipedia.org/wiki/PageRank
6. Google Search Central. "A guide to Google Search ranking systems." developers.google.com/search
7. Search Engine Roundtable. "Google Really Kills Off Toolbar PageRank." seroundtable.com
8. Search Engine Journal. "Is Domain Authority A Google Ranking Factor?" searchenginejournal.com
9. Majestic. "Glossary: Trust Flow, Citation Flow." majestic.com/help/glossary
10. Wikipedia. "2024 Google Search documentation leak." en.wikipedia.org; Mike King, iPullRank. "Secrets from the Algorithm: Google Search’s Internal Engineering Documentation Has Leaked." ipullrank.com/google-algo-leak
11. Google Search Central. "Qualify your outbound links to Google." developers.google.com/search; Google Search Central Blog. "Evolving 'nofollow': new ways to identify the nature of links" (2019). developers.google.com/search/blog
12. Google Search Central. "Spam policies for Google web search." developers.google.com/search
13. Google Search Central Blog. "What web creators should know about our March 2024 core update and new spam policies." developers.google.com/search/blog
14. Google Search Console Help. "Disavow links to your site." support.google.com
15. Google Search Console Help. "Links report." support.google.com
16. Google Search Central. "Creating helpful, reliable, people-first content." developers.google.com/search
17. Ahrefs Blog. "96.55% of Content Gets No Traffic From Google" (2023). ahrefs.com/blog/search-traffic-study
18. Backlinko. "We Analyzed 11.8 Million Google Search Results." backlinko.com/search-engine-ranking
19. Google Search Central Blog. "Penguin is now part of our core algorithm" (2016). developers.google.com/search/blog
20. Google Search Central. "Site moves with URL changes." developers.google.com/search