DA, DR and Authority Scores: Third-Party Metrics in Context
Domain Authority and Domain Rating aren't Google ranking factors. Here is what they measure, why they correlate with rankings, and how to use them correctly.
Domain Authority (Moz) and Domain Rating (Ahrefs) are not Google ranking factors — Google doesn’t read either score, and Google’s own Search Advocate John Mueller has said on record, “we don’t use domain authority at all in our algorithms.” Both metrics are third-party estimates of how strong a site’s backlink profile looks, built by each tool vendor from its own crawl of the web’s link graph. They’re useful for comparing your site against competitors and for triaging which prospective backlinks are worth chasing, but treating a DA or DR number as a proxy for how Google itself will treat your site is where most of the confusion — and most of the wasted effort — comes from.
Key takeaway
- DA and DR are third-party metrics, not Google ranking factors — Google has confirmed directly that it doesn’t use Domain Authority.
- They correlate with rankings because they measure backlink strength, and backlinks genuinely are a ranking signal — the metric is a proxy, not the cause.
- DA and DR are calculated differently and aren’t directly comparable across tools — a 40 on Moz and a 40 on Ahrefs don’t mean the same thing.
- Use these scores for competitive benchmarking and link-prospect triage, not as a target to optimise toward directly.
What Domain Authority and Domain Rating actually measure
Domain Authority is a score from 1 to 100 developed by Moz, calculated by a machine-learning model trained to predict how well a domain is likely to rank based on dozens of factors pulled from Moz’s own link index — primarily the number and quality of linking root domains. Domain Rating is Ahrefs’ equivalent, also scored 1 to 100 on a logarithmic scale, built from Ahrefs’ own backlink index and weighted heavily toward the quantity and strength of unique referring domains. Semrush has its own version too, called Authority Score, which folds in organic traffic estimates alongside link data. All three are estimates of backlink strength built on top of each vendor’s own crawl of the web — not measurements pulled from Google’s index, because no outside tool has access to that.
Why these scores correlate with rankings anyway
If DA and DR aren’t ranking factors, why do higher-scoring sites so often rank better? Because the underlying thing these tools measure — a large, diverse base of referring domains, many of them themselves authoritative — genuinely is something Google’s ranking systems reward, just not through the DA or DR number itself. A site earns backlinks from strong domains over years by publishing genuinely useful, cited content, building brand recognition, and accumulating editorial trust. That same activity produces a rising DA/DR score and better rankings, roughly in parallel, because both are downstream of the same cause. The metric is a symptom of authority, not the mechanism that creates it.
How DA, DR and Authority Score compare
| Metric | Vendor | Scale | Primary inputs |
|---|---|---|---|
| Domain Authority (DA) | Moz | 1-100, logarithmic | Linking root domains, MozRank, MozTrust, spam signals |
| Domain Rating (DR) | Ahrefs | 1-100, logarithmic | Number and strength of unique referring domains |
| Authority Score | Semrush | 1-100 | Backlink data blended with organic traffic estimates |
| Trust Flow / Citation Flow | Majestic | 1-100 each | Link quality (trust) separated from link quantity (citation) |
Because each tool crawls a different slice of the web and weights inputs differently, the same domain can carry meaningfully different scores across tools. A site with a DA of 35 and a DR of 55 isn’t showing an error — it’s showing two different models drawing from two different link indexes with two different formulas. Comparing your DA to a competitor’s DR is comparing figures that were never designed to line up.
What these scores are genuinely useful for
Despite not being ranking factors, DA and DR earn their place in an SEO workflow for a few specific jobs:
- Competitive benchmarking. Tracking your own DA/DR against direct competitors over time shows whether your backlink profile is growing relative to the field you’re actually competing with.
- Link prospect triage. When evaluating dozens of potential guest-post or outreach targets, DA/DR gives a fast first filter — not a final verdict, but a reasonable way to sort a long list before doing deeper relevance and traffic checks.
- Spotting spam and low-quality sites. A site with an unusually high DA relative to its actual traffic and content quality is often running a manipulative link scheme; the mismatch itself is a useful red flag.
- Tracking your own progress. A steadily rising score over months is a reasonable proxy that your link-earning efforts are compounding, even though the score itself isn’t the target.
“We don’t use domain authority at all”
Google’s Search Advocate John Mueller has stated directly, on record, that Google does not use Moz’s Domain Authority metric in its ranking systems. The same applies to Ahrefs’ Domain Rating and every other third-party authority score — none of them are inputs Google’s algorithms read.
Source — John Mueller, Google Search Advocate, public statements on Domain Authority
Where relying on DA/DR goes wrong
The most common mistake is treating DA or DR as a link-acquisition scorecard — chasing links exclusively from domains above a certain threshold, regardless of topical relevance, and rejecting genuinely valuable links from smaller, niche-relevant sites because the number looks unimpressive. A link from a moderately-scored blog that covers your exact industry, written by someone who reads your content and cites it because it’s useful, is very often worth more to your actual rankings than a link bought or begged from an unrelated high-DA site padded with thin content. Relevance and editorial context matter more than the score attached to the domain — a point covered in more depth in our piece on relevance versus authority in link value.
The second common mistake is comparing scores across tools as though they’re interchangeable, or assuming a specific DA number is required before link building “counts.” There’s no threshold at which links stop working below a certain domain score, and there’s no ceiling above which more links stop helping — what changes is how much marginal signal each additional link realistically adds, which ties back to the underlying question of how many backlinks you actually need to rank for a given term.
How to check and use your own score correctly
- Pick one tool (Moz, Ahrefs, or Semrush) and track your score in that tool consistently — don’t switch metrics month to month, since the scales aren’t comparable.
- Benchmark against 3-5 direct competitors in the same tool, not against unrelated “authority” sites in different industries.
- Watch the trend line over quarters, not the absolute number in isolation — a steady rise matters more than where you sit today.
- When using the score to triage link prospects, pair it with a manual relevance check and a quick look at the site’s actual organic traffic — a high score with negligible real traffic is a spam warning sign, not a quality signal.
- Never reject a genuinely relevant, editorially-earned link opportunity purely because the domain’s score falls below an arbitrary cutoff.
Frequently asked questions
Is Domain Authority a Google ranking factor?
No. Domain Authority is a Moz metric that Google does not read or use in its ranking systems. Google’s John Mueller has confirmed this directly. DA correlates with rankings because it measures backlink strength, which genuinely is a ranking signal — but the score itself is not.
What’s a good Domain Authority or Domain Rating score?
There’s no universal “good” number — it depends entirely on your niche and who you’re competing against. A DA of 30 can be strong for a niche local business site and weak for a national ecommerce brand. Always benchmark against direct competitors in the same tool rather than a generic target.
Why do my DA and DR scores differ so much?
Moz and Ahrefs each crawl a different slice of the web and calculate their scores with different formulas and inputs. The two numbers were never designed to align, so a gap between them is expected and doesn’t indicate an error on either side.
Can I increase my Domain Authority directly?
Not directly — there’s no setting to optimise for DA itself. It rises as a byproduct of earning backlinks from a growing number of quality, relevant referring domains over time, the same activity that also improves actual rankings.
Should I reject a link opportunity if the site’s DA is low?
Not automatically. A topically relevant, editorially genuine link from a lower-scored site in your exact niche is often worth more than an unrelated high-DA placement. Use the score as one input alongside relevance and real traffic, not the sole deciding factor.
Does a high Domain Authority protect against Google penalties?
No. DA reflects link profile strength, not compliance with Google’s guidelines. Sites with high DA scores have received manual actions for unnatural links, and the score offers no protection against algorithmic demotions tied to spam or low-quality content.
The bottom line
DA, DR, and Authority Score are genuinely useful comparative tools — for tracking your own progress, benchmarking against competitors, and triaging a long list of link prospects. They stop being useful the moment they become the target instead of the proxy. Build for the things that actually move rankings — relevant, editorially-earned links from sites your audience trusts — and let the score follow, not lead. For the fundamentals of what still works, see our link building guide, and for the underlying debate on whether links still matter at all, read do backlinks still matter.
Need help interpreting your own backlink profile or building toward the right competitors, not a vanity score? See our one-time SEO services.
