What Domain Authority is, and why Google does not use it

Domain Authority is a predictive score from 0 to 100 created by Moz, an SEO software company, to estimate how likely one website is to rank well compared with others. Domain Authority is a third-party vendor score rather than a Google metric, and Google does not use it to rank anything.

That sentence is the most important fact on this topic and belongs before everything else, because the belief that Domain Authority is a Google score is what leads people to pay for links from sites with attractive numbers and get nothing back. This article covers where the score comes from, how it differs from Ahrefs Domain Rating, when it is worth looking at, and how to build real authority without buying links.

What Domain Authority is and who created it

Domain Authority was developed by Moz. The score is calculated from the link index Moz collects itself, fed into a model Moz trains to predict how well a site is likely to rank relative to other sites in the same index. The output is compressed onto a 0 to 100 scale.

Two properties matter before you use the number for anything:

• The scale is logarithmic. Moving from 20 to 30 is far easier than moving from 70 to 80, so one point near the top of the range represents many times the work of one point near the bottom.
• It is relative to the whole index at the moment of calculation. When the vendor recrawls the web or adjusts its model, your score can move even though nothing about your links changed.

That second property explains the common panic about a score dropping for no apparent reason. Usually the site did not get worse. The reference line everything is measured against moved.

Is it true that Domain Authority is not a Google ranking factor?

Yes, it is true. Google has stated repeatedly that it does not use scores from third-party SEO tools, whether those scores claim to measure a site's authority or its spamminess, and Google representatives have added that Google does not treat authority as one site-wide number the way these tools present it.

So what is the score good for? It is useful as a sorting aid when you need to compare many sites at once under one consistent rule, such as working through a list of sites linking to a competitor and deciding who to approach first. It sorts a list faster than opening every site by hand. It is not a decision criterion, and it should never be the reported outcome of an SEO programme, because the real outcomes are rankings for the queries you care about, the traffic arriving, and the customers produced.

The practical consequence is that any proposal selling you a projected increase in Domain Authority is selling you a software vendor's number rather than a result on the search results page.

How Domain Authority differs from Ahrefs Domain Rating

Both are logarithmic 0 to 100 scores, computed by different software vendors, from different link indexes, using formulas neither vendor fully discloses. The consequence is that the two cannot be compared with each other, and neither can scores taken from different tools.

The difference worth remembering is that Domain Rating is derived mainly from the backlink profile, looking at how many domains link to a site and how strong those domains are, while Domain Authority is the output of a model trained to predict ranking ability. The two answer different questions, so the same site can carry scores tens of points apart with nothing wrong anywhere.

When a report lands on your desk saying only that a site scores 45, the first questions are whose 45, measured when, and against which data set. Without those three, the number is no better than one plucked from the air.

What Domain Authority counts as good

There is no correct threshold, and anyone naming a specific number is inventing a rule. The reasoning has two layers. First, the score is relative, so the same figure means different things in different industries. A national news site and a specialist parts manufacturer are not playing on the same field. Second, the score is not an input to Google in the first place, so chasing a target figure means chasing a target that is not connected to the result you want.

The defensible way to use the score is relatively, within one set. Pull the list of sites linking to three competitors in your market, measure every site with the same tool on the same day, and see where you sit in the group. The output is not a grade. It is a rough picture of how wide the gap is, and the more useful question it prompts is which sites link to competitors but not to you, and what kind of work earned those links.

How to check Domain Authority for free

Free checkers fall into three categories, and each has limits worth knowing before you trust the figure.

• The score vendor's own free tools. These usually require an account and cap how many lookups you get per month. The advantage is that the number comes straight from the source. The drawback is that the allowance rarely covers checking dozens of sites.
• Browser extensions from the same vendors, which overlay scores directly on the search results page. Useful for a quick overview, though the displayed figures are typically cached rather than freshly computed.
• Third-party free checkers that pull data through a vendor's interface. Be careful here, because some of these sites do not display the vendor's score at all and instead compute their own number under a similar sounding name. Confirm whose score you are actually looking at before recording it.

Whichever route you take, record the date and the tool name every time, and always re-measure with the same tool. Comparing figures taken from different vendors or different months and concluding that things improved or worsened is the single most common error in SEO reporting.

How to raise Domain Authority without buying links

Because the score is computed from the link profile, what moves it is the number and quality of domains linking to you. The work that pays off is work that gives other people a reason to cite you.

1. Publish something citable, such as data you collect from your own operations, a guide that goes deeper than anything else available, or a small calculator people in your field use repeatedly. Content anyone could have written attracts no links.
2. Become a source for trade press and industry associations. Journalists and editors need people who can answer a specialist question the same day, and being genuinely reachable earns links that cannot be bought.
3. Recover lost links. Find pages that used to receive links and now return a not-found error, then redirect them to the closest equivalent page. This pays quickly because the links already exist.
4. Chase unlinked brand mentions. When an article names you without linking, asking for the link added is a reasonable request that often succeeds.
5. Consolidate your domain to one version. If the site answers on both the www and non-www hostnames, or over both http and https, without clean redirects, link value ends up split across versions. A technical SEO audit catches problems like that in one pass.
6. Work with the partners you already have. Corporate customers, associations, universities, and events you sponsor all maintain pages listing the organisations involved, and asking to be listed correctly with a link is ordinary practice.

All of this is visibly slower than paying for links. It also compounds, and it never comes back to damage the site later. If you want the process run continuously by someone, a link building service handles it systematically from prospecting through to follow-up.

Why buying backlinks from high-scoring sites does not move rankings

First, plainly: buying or selling links for ranking purposes goes directly against Google's spam policies, which classify the behaviour as link spam. The consequences range from the link being devalued so completely that it does nothing, through to action being taken against the site. This article offers no workaround, because there is no safe workaround.

As for the mechanics of why expensive links from high-scoring sites so often change nothing, several layers are at work.

• The score describes a domain, while the link you bought sits on one page. That page may have no visitors, no links of its own, and no topical connection to your business. A domain-level number says nothing about it.
• Sites that sell links usually sell to many buyers. A page carrying a dozen outbound links to unrelated businesses forms a pattern that is not difficult to recognise.
• Topical relevance matters more than the figure. A link from a travel site to an industrial parts supplier carries no sensible signal, no matter how high the travel site scores.
• The link may be marked as not passing value or as sponsored content, which is the correct treatment for paid placements, and which also means what you paid for is not doing what the seller implied.
• Your problem may never have been links. If the target page does not answer the intent behind the query, or the site has crawling problems, adding links does not address the cause.

The check to run before making any decision about a link is to open the page where the link would appear and look at it. Ask whether anyone reads this page if rankings are taken out of the picture, and what reason the author has to mention you. If neither question has an answer, the link is worthless regardless of the number printed beside the site name. That same test is what selects targets in a properly run backlink service.

What this means in the Thai market

Conditions in Thailand make this score even easier to misread. First, the link indexes maintained by Western tool vendors cover Thai-language sites less completely than English ones. A Thai site with a real reputation in its own sector can therefore carry a lower score than it deserves, simply because part of its link profile sits in places the crawler covers thinly.

Second, a large share of Thai online conversation happens in places that generate no links at all, such as chat groups and in-app content that is closed to crawlers. Brand reputation in Thailand often grows faster than any tool can see. Using the score as your only measure of progress means missing what is actually happening.

Third, there is an active market in link placements on Thai-language sites built specifically to accept paid articles. Those sites usually show attractive numbers while having no real readership, no editor, and a pile of articles from unrelated businesses. Judging by eye whether anyone reads the page filters them out better than any score does.

Fourth, many Thai sites run two languages on separate URL structures, and configuring the relationship between the two correctly affects which version gets indexed and shown. That work sits closer to hand and pays back faster than chasing a score, and it belongs to SEO for the Thai market that should be finished before link investment begins.

FAQ about Domain Authority

Why did my Domain Authority drop when I did nothing wrong?

The usual cause is the vendor recrawling the web or adjusting its model, which moves the reference line for everybody at once, so your score changes although none of your links disappeared. Before worrying, check whether the number of referring domains actually fell. If it did not, the change came from the tool.

My Domain Authority and Domain Rating differ a lot, which should I trust?

Neither needs to be trusted over the other, because they are scores from different software vendors computed from different link indexes. What helps is picking one tool and staying with it for the whole programme so internal comparisons hold, then judging results by rankings, traffic, and customers instead.

What score should a new site target in its first year?

A new site should set no score target at all. Targets that can be measured and that connect to revenue are new referring domains per quarter, queries reaching page one, and enquiries arriving from search. The score follows that work on its own as the link profile grows.

Are links from low-scoring sites useless?

No. A link from a specialist site with real readers in your industry is worth more than a link from a high-scoring general site with no connection to what you sell. The test to apply is whether the page has readers, whether its subject relates to your business, and whether being mentioned there gives a reader a reason to contact you.

If your aim is to be cited more often without taking risks against Google's policies, the starting point is knowing who links to you today, who links to your competitors, and where the gap sits. Relevant Audience plans and runs link acquisition for businesses in Thailand, with reporting measured in rankings and customers rather than a vendor's score.