Domain Authority: What DA, DR and Authority Score Actually Measure, and Why Raising Them Is the Wrong Goal

Three vendors, three formulas, and one name everyone borrows

"Domain authority" is the name of Moz's metric, but people use it for any score that grades a website's links from 0 or 1 up to 100. Ahrefs calls its version Domain Rating. Semrush calls its version Authority Score. Each is built from that company's own index of links, which means three tools can look at the same bakery's website and return three different numbers, and none of them is wrong by its own rules.

That is the first thing to understand, and most of what follows depends on it. These are product features, designed to help subscribers compare sites. They are not readouts from Google, and they are not measurements of anything Google has published. The table sets out what each vendor documents about its own score as of October 2026.

Inside Domain Rating: a pie each linking site cuts into equal slices

Ahrefs explains its calculation in a help article on Domain Rating. A site with a higher rating passes more value to the sites it links to. Each source domain splits its rating equally among all the domains it links to. Ahrefs repeats the calculation across its database until every domain has a value, then scales those values into the 0 to 100 range.

The equal split has a consequence that surprises people. Ahrefs' own example compares a small site linking to three domains with a giant linking to a million, and says the small site's link can count for more. A famous directory that links to everyone is handing out very thin slices.

• DR is relative. Ahrefs says it is not possible to call a DR of 30, 50 or 70 good, because each number only means something next to other sites.
• Your DR can fall while you lose nothing. If other sites gain links faster, you slide down the scale. Ahrefs says the top of the scale cannot rise past 100, so growth elsewhere pushes everyone else down.
• It is site-wide. DR grades the domain. Ahrefs offers a separate page-level score, URL Rating, and says DR correlates with Google rankings less well than URL Rating does. That is Ahrefs' claim about its own metrics, not something Google has said.
• Topic and place are not inputs. Nothing in the calculation Ahrefs describes asks whether the linking site covers your trade or your town. Ahrefs lists topical relevance among the separate things to check before trusting a site.

Read that list again as a link seller would. A network of small sites, each linking out to a handful of clients, is a tidy way to manufacture DR. That is part of why our guide to high quality backlinks judges links by relevance, readers and who chose them, before any score.

Inside Authority Score: links, traffic and a built-in spam filter

Semrush takes a different route. Its knowledge base article on Authority Score describes a compound metric on a 1 to 100 scale, built from eight weighted factors grouped into three facets. Link Power counts follow referring domains and weighs their authority. Organic Traffic estimates monthly visits from a site's keyword positions and the click potential of each position. Natural Profile runs a series of checks for suspicious behavior.

Three more details from the same article matter for anyone trying to move the number. Extra links from a site that already links to you do not raise it. A link's impact depends strongly on your niche. And a score can drop because competitors in that niche outperformed you, because the backlink profile is weak, or because of a negative SEO attack. Semrush also says it is highly unlikely that a Google penalty affects the score, which is the clearest possible evidence that Authority Score and Google's view of a site are separate things.

What Google has published about links, and the scores it never mentions

Google's documentation does not mention Domain Authority, Domain Rating or Authority Score anywhere we could find, and it does not describe any single site-wide authority number of its own. What it does say is specific. Its guide to ranking systems says Google has various systems that understand how pages link to each other, that PageRank was one of its core ranking systems at launch, and that how PageRank works has evolved a lot since then and remains part of the core systems.

The same guide says Google's ranking systems are designed to work on the page level, while site-wide signals and classifiers also contribute, and that good site-wide signals do not mean all of a site's content will rank highly. The SEO Starter Guide adds that PageRank is just one of many ranking signals, and that there is much more to Google Search than links.

So treat the scores as an outside estimate of one input among many. Our page on Google ranking factors sorts what Google has confirmed from what the industry assumes.

How a vanity number steers a link budget the wrong way

Any measure turned into a target starts rewarding the cheapest way to hit it. With authority scores the cheapest way is usually the worst link a business can buy. The offers in an owner's inbox are priced by DR or DA for a reason: sellers can manufacture the number, and buyers cannot easily check whether anyone reads the site behind it.

Google's spam policies define link spam as creating links primarily to manipulate search rankings, and list buying links among the examples. A campaign aimed at a score drifts toward exactly that. It also drifts away from the links that send customers: the supplier's dealer page, the chamber directory, the local reporter's story. Those may barely move DR, and they are worth more than ten points of it. Our guide to buying backlinks covers what the score-priced packages really contain.

A score you can buy is a score that tells you what you bought, not what you earned.

The relative scales add a quieter problem. A plumber who earns six good links in a year can watch DR fall because the web grew faster. Fire the agency over that and you have punished the right work for a number that moved for someone else's reasons.

Using the scores the way their makers intend

None of this makes the tools useless. Both vendors say their scores are for comparison, and comparison is genuinely helpful. The rule is to stay inside one tool, because Ahrefs, Semrush and Moz crawl different slices of the web and score on different models. Here is a half-hour comparison that uses a score without being led by it.

1. 1

   List five competitors that outrank you

   Use the businesses above you for your two or three most valuable searches, not national brands you will never compete with.

2. 2

   Pull each one's score and referring domains in one tool

   Write down the authority score and the count of referring domains. The gap tells you roughly how far behind you are in links, which is all the score can tell you.

3. 3

   Open the referring domains, not the score

   Export the domains linking to each competitor. Look for sites that link to two or more of them and not to you: suppliers, associations, local media, event pages.

4. 4

   Read each shared site as a customer would

   Keep the ones your customers would recognize. Discard the ones with no audience, whatever their score.

5. 5

   Turn the shortlist into outreach

   That list is a better plan than any target number. Our guide on how to get backlinks covers the asks that work for each kind of site.

If you do not want a subscription for this, our competitor analysis does the same work, and Ahrefs vs Semrush compares the two tools if you would rather buy one. A link building tools roundup covers the cheaper and free options.

What to measure instead of domain authority

Swap the score for numbers that describe what links are supposed to do: help the right pages rank and send people who might buy. Every item below comes from Search Console, analytics or your own records, so no vendor's model sits between you and the result.

Links also help in a place the scores do not count. AI answers lean on what other sites say about a business, mentions included, which our page on brand mentions versus backlinks explains. For the wider set of numbers worth reporting, see SEO KPIs.

When a report leads with DA, ask these questions

An agency that reports an authority score as its headline result is reporting the easiest number to move and the hardest to connect to revenue. That is not proof of bad work, but it earns a few questions: which links did you earn this month, and from whom? Which pages did they point to, and did those pages gain clicks? Did any link cost money, and was it marked sponsored? If the answers are vague, the work probably is too. A backlink audit will show what was actually built in your name.

DataCram's monthly SEO programs report links earned, rankings and the leads behind them, and treat third-party scores as a footnote. There is no long contract and the scope is defined; programs start at $625 a month and most local businesses land between $625 and $2,250, per our SEO pricing. If you want to start with the site itself, the free website audit emails a report on speed, SEO, mobile, security and content. The link building hub lays out the rest of the craft, in order.