DR vs DA: What's the Difference, and Which One Should You Trust?

What is DR (Domain Rating)?

Domain Rating is a metric published by Ahrefs. It estimates the strength of a website's backlink profile on a 0-100 logarithmic scale, based on the quantity and quality of external sites linking to it, as measured by Ahrefs' own web crawler and link index. Ahrefs' own Help Center puts it directly: "Domain Rating (DR) shows the strength of a website's backlink profile compared to the others in [Ahrefs'] database on a 100-point scale."

DR is domain-wide, not page-specific — it scores an entire domain's backlink profile, and Ahrefs treats it as distinct from its own page-level URL Rating (UR) metric. That distinction is more than technical trivia. Ahrefs' own documentation notes that DR "correlates with Google rankings pretty well," but not as well as UR does, because Google ultimately ranks individual pages, not whole domains.

Ahrefs also publishes its own correlation finding: its Help Center states that "our study found a correlation between the DR of the website and the number of keywords it ranks for," which the company says can be used to estimate a site's ability to earn organic traffic. That is a correlation, not a causal claim. Ahrefs frames it as an estimate of ranking potential, not proof that raising DR directly raises rankings — sites that already rank well also tend to accumulate more links over time, so the causation could run in either direction, or both.

How does Ahrefs actually calculate DR?

Ahrefs has not published DR's exact formula — no vendor in this space discloses its literal weights and code — but it has published the mechanics behind the score, in its Help Center and SEO glossary:

• DR is built from a "link juice" model: authority flows between domains through backlinks, and a higher-DR linking domain passes more of it along.
• A linking domain splits its own rating equally across every domain it links out to. A modest domain that links to only three other sites passes more weight to each of them than a much stronger domain that links out to a million pages.
• Nofollow links do not pass DR.
• The resulting raw value is rescaled into the public 0-100 range, and Ahrefs describes DR as a less granular, public-facing version of a more precise internal metric it calls Ahrefs Rank.
• The scale is logarithmic, not linear. Ahrefs says the gap between DR 75 and DR 76 represents far more underlying link equity than the gap between DR 20 and DR 21 — the higher the score, the harder each additional point becomes to earn.

The practical upshot: a DR score is a snapshot of a domain's position in Ahrefs' link graph at the time of the last crawl, not a fixed, permanent property of the site.

What is DA (Domain Authority)?

Domain Authority is a separate metric published by Moz. It also scores a domain on a roughly 1-100 logarithmic scale and is also backlink-based, but it comes from Moz's own crawler, its own link index, and its own scoring model — a different dataset producing a different number. Moz's own Guide to Domain Authority 2.0 states this plainly: "Domain Authority (DA) predicts the ranking ability of a website" on "a 1-100 logarithmic scale," where "higher DA scores indicate a higher chance of ranking in search engine results." The same guide is explicit that "Domain Authority scores are based on factors from a domain's inbound links (backlinks)."

How does Moz actually calculate DA?

Where Ahrefs describes DR as a link-equity flow calculation, Moz describes DA as a machine-learned model. Since the DA 2.0 rebuild, Moz trains the score by searching for the model that best predicts real Google rankings from link data, rather than applying one fixed formula. Russ Jones, who was Moz's principal search scientist at the time, told Search Engine Land that the rebuilt model replaced "a complex linear regression model" with "a neural network, meaning DA will get 'smarter' and more accurate over time." Jones also said Moz started "seed[ing] random non-ranking pages into the last position occasionally so the model can learn about sites that never rank at all" — a fix for a known blind spot in the old model.

Two more inputs feed the score. Moz's own DA 2.0 guide says DA factors in "Spam Score and link quality patterns" — Moz's own signal for manipulative link behavior — on top of the machine-learned model itself, which draws on Moz's Link Explorer index, described to Search Engine Land as tracking "over 35 trillion links."

Moz also publishes a page-level counterpart, Page Authority (PA), mirroring the domain-versus-page split Ahrefs draws between DR and UR. Both vendors, in other words, separate a whole-domain score from a single-page score: DA and DR describe the site, PA and UR describe the specific page a link or ranking actually depends on.

When did Moz rebuild DA, and why does it matter?

DA has not run on an unchanged formula since it launched. Moz's own Guide to Domain Authority 2.0 documents a specific rebuild timeline: historical DA and Page Authority tracking began in September 2017, Moz rebuilt its underlying link index in April 2018 — which it describes as making that index "35x bigger and 30x fresher" — and shipped a new scoring algorithm, Domain Authority 2.0, in March 2019. Search Engine Land's coverage of the launch dates it to March 5, 2019.

Moz's own guide warns customers directly that scores would move because of the update itself, not because of anything happening on their site: "If you monitor your site's Domain Authority, you can expect to notice some changes... This is due to the update in how we calculate scores and is not a direct reflection of a change you've made to your link building strategy." That is a useful caution for anyone tracking DR or DA over time: a score change can reflect a vendor recalibrating its model, not a real change in a site's backlink profile.

Ahrefs has not published a comparably named, dated recalibration for DR. That does not mean DR never moves — any link-graph score shifts as the index behind it is recrawled — only that Ahrefs has not documented a "DR 2.0"-style event the way Moz documented DA 2.0.

Why can the same site show different DR and DA?

DR and DA are not two views of the same underlying number. Ahrefs and Moz each crawl the web independently, so they see a different, overlapping-but-not-identical set of backlinks for any given site, and each runs its own model over what it finds. A site can reasonably show DR 45 and DA 30, or the reverse — that gap is not an error, it reflects two different measurement systems built from two different indexes.

This pattern is not unique to DR and DA. Semrush publishes a comparable score of its own, Authority Score, also on a 1-100 scale, but built differently again: Semrush's own knowledge base describes it as a blend of "Link Power," "Organic Traffic," and spam-related "Natural Profile" factors, meaning Semrush folds actual estimated traffic into its formula in a way neither Ahrefs nor Moz does for DR or DA. Semrush gives the same guidance as the other two vendors: the score is "best used for domain comparison, and not for determining good/bad on an absolute scale." Three companies, three independent crawls, three different formulas — none of them interchangeable, and none of them Google's.

What has Google actually said about DR, DA, and similar metrics?

The clearest official statement comes from Google itself. Google's own Search Central documentation on third-party SEO tools warns that "third-party tools don't have access to our internal ranking data. They can't guarantee performance," and cautions that "Google doesn't evaluate third-party services," so treat with skepticism any claim that a tool's output is "somehow 'acceptable' or 'approved' by Google Search." That page does not name DR or DA specifically, but its warning covers any third-party authority score, including both.

Google engineers have been more specific in public comments over the years. Paul Haahr, a senior Google engineer, told Search Engine Land that Google has no single internal "authority" score at all: "We have no one signal that we'll say, 'This is authority.'" Gary Illyes, asked directly about Domain Authority, told Search Engine Land, "We don't use it, and it doesn't align with anything we have at Google." John Mueller has repeated the same point across several years, as Search Engine Journal has documented: from a 2016 comment that "Google doesn't use domain authority," through a 2020 statement that Google "doesn't use Domain Authority at all when it comes to Search crawling, indexing, or ranking," to a 2022 reply that "you do not need DA for Google Search. Google doesn't use it at all."

Both vendors say the same thing about their own metrics. According to Ahrefs' own Help Center, "there's no evidence that search engines use Domain Rating (or similar scores such as Domain Authority, the power of domain, etc) as a ranking factor at all." Moz's own DA 2.0 guide tells customers not to "mistake DA for PageRank, Google's link-based ranking signal," because "DA was created by Moz, and Google doesn't factor the score into your site's ranking."

How do DR and DA get misused?

The most common misuse is treating either score as a sole vetting criterion for a backlink purchase. Both scores measure link-graph position, not real audience, real trust, or real editorial standards — and link-graph position is the one part of this equation a determined operator can manufacture.

Search Engine Land's guide to private blog networks explains the mechanism: a PBN is "a group of websites created to pass link equity to a single site," typically built on expired or low-value domains "designed to attract a few users, with minimal engagement from those users who do visit," often running "generic, scraped, AI-generated, or duplicate content." None of that stops the network from pushing up a target's authority score, because link count and link position are exactly what DR and DA measure. Google treats this as manipulation, not a metrics quirk — the same guide notes Google "first issued widespread manual actions against PBNs in 2014," and PBN-style link schemes fall under Google's link-spam policies today.

The resulting gap between authority score and real quality is not small. An analysis of more than 150,000 backlink marketplace listings by Saaslinks found that roughly one in five sites with DR 70 or higher gets fewer than 1,000 organic visits a month, and that 37 percent of DR 80+ sites in its sample fell under that same traffic threshold. Its conclusion: "Domain Rating measures the strength of a site's backlink profile, not its traffic — and a backlink profile is exactly the thing a determined operator can manufacture." The same logic applies to DA, which is also link-graph-based.

Neither vendor disputes this. Moz's own Russ Jones, discussing how SEOs should use DA, told Search Engine Land that "Domain Authority is meaningless when it isn't compared to other sites, full stop," warning that "issues only arise when webmasters fixate on one metric, whether that is Domain Authority or anything else." Treating a single DR or DA number as a pass/fail gate for a backlink purchase is precisely the fixation he was warning against. A real vetting process checks organic traffic, topical relevance, and editorial history alongside whatever authority score a tool reports, not instead of it.

DR vs DA at a glance

Which one should you use?

Use whichever one matches the tool you already have a subscription to, and be explicit about which one you're quoting. "DR 60" and "DA 60" are not interchangeable, and a marketplace or report that quotes one without naming the source is asking you to trust a number it hasn't identified.

Whichever score you use, treat it as a comparison, not a verdict. Ahrefs frames DR as a way to estimate ranking potential relative to other sites in its own index; Moz's own guidance is to aim for a score higher than your direct competitors, not to chase a fixed target. Pair either score with real organic traffic data before trusting it as a signal of quality — the gap between a high authority score and real traffic is exactly where manufactured link profiles hide.

Both companies also let you check the score without a paid subscription. Ahrefs' own Website Authority Checker shows a domain's DR directly, describing itself as a way to "check the 'authority' of your domain (as measured by Ahrefs)," and Moz offers a comparable free lookup through its own site and the MozBar browser extension. Neither free tier replaces the fuller paid data each vendor sells, but either is enough to confirm which number a report is actually quoting before you trust it.