Google does not use Domain Authority or any third-party score. What DA, DR and Authority Score measure, where they mislead, and what to check instead.
No. Google does not use Domain Authority, or any other third-party authority score, to rank pages. John Mueller of Google said so directly in 2023: "Google does not use scores from third-party SEO tools for search." That does not make the scores useless. Moz's Domain Authority, Ahrefs' Domain Rating and Semrush's Authority Score are each a tool's own estimate, built from that tool's own data, and each is meant for comparing sites. Here is what each score measures, where it misleads, and what to check before you pay for a link on a site with a high DA.
What Google says about these scores
Mueller explained Google's stance on scores from third-party SEO tools in an Ask Googlebot episode reported by Search Engine Journal in August 2023. His answer covered authority and spam scores alike. Search Engine Journal summed it up this way: Google does not consider scores about a website's authority or spamminess from external SEO tools when deciding where to rank a site.
Mueller did not call the scores worthless. He said that transparently calculated scores can help you estimate where your site stands or point out real issues. He stressed understanding how a score is calculated, so the useful question is what a given score is calculated from, and whether that matches what you are trying to judge.
What DA, DR and Authority Score measure
Each of the three scores is built differently.
Domain Authority (Moz). Moz's own explainer describes DA as a score that "predicts how likely a website is to rank" compared to competitors, on a scale from 1 to 100. Moz also says that "Domain Authority is not a direct ranking factor" and that it is a comparative metric.
Domain Rating (Ahrefs). Ahrefs' help page says DR shows the strength of a site's backlink profile "compared to the others in our database on a 100-point scale". It counts how many domains link to a site and how many other sites each of those domains links to. Because it is relative, Ahrefs says your DR can drop even when you lose no links, if other sites gain more.
Authority Score (Semrush). Semrush's knowledge base calls Authority Score "our compound metric that grades the overall quality of a website or a webpage." It is built from link power, estimated organic traffic and a set of spam checks, such as too many referring domains on the same IP address.
All three vendors frame their score as relative. Ahrefs says no single Domain Rating can be called good in absolute terms, because the metric is relative by definition. Semrush says Authority Score "is best used for domain comparison, and not for determining good/bad on an absolute scale."
Where a high score misleads
A score built mostly from links can be pushed up with links. Semrush, for one, treats too many referring domains on the same IP address or network as "a sign of a manipulated link profile", so a high number on its own proves little about a site. Our look at link packages sold as AI visibility on the strength of a DR number shows how those offers use it.
The vendors' own pages point to the gaps:
- Links alone do not show whether real people visit. Semrush's Authority Score adds organic traffic and spam checks to link data. One of its labels, "Poor traffic-to-backlink ratio", flags sites with many backlinks but little organic traffic.
- A site-wide score says nothing about the page your link sits on. Ahrefs notes that DR is calculated at the domain level, while its URL Rating looks at individual pages.
- Relevance is not in the number. Ahrefs advises that "You should never judge the quality of a website on site-wide" authority alone, and lists topical relevance among the things to check.
Google's spam policies are what decide whether a bought link is a problem. They list "Buying or selling links for ranking purposes" as link spam, whatever the selling site's score.
What to check instead of DA
Ahrefs' help page lists questions to ask before you get a link from a site, in addition to its score:
- Do they have high-quality backlinks?
- Do they link out to a lot of websites? Fewer tends to be better.
- Are they publishing high-quality content?
- Is the site likely to still be around in six months, a year, five years?
- Does it get any organic traffic, and is it topically relevant to yours?
One more check comes from Google's spam policies: if you pay for the link, ask how it will be marked, since Google says paid links should carry a rel value such as sponsored or nofollow.
How to judge a link after you have it
A score cannot tell you what one link did for you. These checks get you closer:
- Is the link live and followed? SerpCrest's Bulk DoFollow / NoFollow Checker checks a list of URLs at once for whether each backlink is live, dofollow and indexed.
- Did the target page move? The Keyword Rank Checker shows where a site ranks on Google right now for a short list of keywords, by country. Run it before the link goes live and again a few weeks later. It is a live check, not tracking over time, so keep your own record, and remember that rankings can move for reasons other than the link.
- Did it send visitors? Check referral traffic from the linking page in your analytics.
If you are paying for the link, our breakdown of what backlinks cost by link type shows where prices come from.
The bottom line
Use DA, DR or Authority Score to compare sites quickly, the way their makers intend. Don't treat any of them as a Google signal, and don't let a high number stand in for checking the site's traffic, relevance and links out.
