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If purchasing a domain name with an existing, or recent, website, one important consideration is how authoritative that website is compared to other websites in the same sector.

If you have plans to develop the domain, that will indicate a starting point you may be able to build upon. Strong authority will also make the domain name more valuable if you plan to resell to an end user.

This article does not attempt to be a guide to improving website authority and search engine optimization (SEO). It will, however, provide a brief introduction to two commonly used instruments.

Moz Domain Authority, DA

Moz is one of the leading providers of information and tools to measure and optimize websites. Their software has indexed about 44 trillion links, over more than 700 million different keywords.

Moz Domain Authority (DA) is a measure, on a scale from 1 to 100, on how authoritative search engines are expected to rank a website.

In the article What is Domain Authority and Why Is It Important?, they describe DA this way:
Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how likely a website is to rank in search engine result pages (SERPs). Domain Authority scores range from one to 100, with higher scores corresponding to greater likelihood of ranking.

While Moz uses several dozen inputs into the algorithm for DA, it is highly dependent on the number of other sites that link to this site, and the authority of those sites.

Even if your site has not changed, its DA may change, as it is a ranking relative to other websites. If your competition make their sites stronger, your DA will go down.

Starting a few years ago, Moz now use machine learning in the DA computational engine, meaning that the weighting of the factors constantly adjust to better match how search engines rank pages.

You can get 10 free link queries per month using the Moz Link Explorer by signing up for a free account. For more features and additional evaluations, they offer a paid Moz Pro subscription.

Moz also offers a Chrome extension for Moz Link Explorer.

Even on the Moz free plan, you get a wealth of useful information. It shows the domain authority DA score, as well as how that has changed over the past year. In addition, the number of sites that link in to this website, how that has changed, and a histogram of the authority of the sites that link in. The data can be exported in a CSV format if you want to do further analysis. Keep in mind you can only analyze 10 per month, though, on the free plan.

Ahrefs Domain Rating, DR

Another well-known service in the SEO sector is Ahrefs. Ahrefs have their own authority rating, that also runs from 1 to 100, called Domain Rating DR.

The Ahrefs DR is based exclusively on link data, so aspects like search traffic or domain age don’t enter into the calculation. Ahrefs DR only takes into account do-follow links.

If the domain that links to your site also links to many other sites, the impact on your DR will be less. Tim Soulo, CMO at Ahrefs, published an explanation Domain Rating: What It Is and What It’s Good For.
1. We find all domains that have at least one followed link to the target domain.
2. We look up how many other domains each linking domain links to.
3. We then pass some amount of “DR juice” from each linking domain to the target domain. That amount is determined (roughly) by dividing the DR of the linking domain by the number of unique domains that it links to.

The Ahrefs DR score is logarithmic, so the difference between a site that scores 81 and one at 80 is much more than the difference between a DR 3 site compared to a DR 2 site.

You can check Ahrefs DR for a site using the Website Authority Tool, one of the free Ahrefs SEO Tools.

Ahrefs Webmaster Tools are a paid alternative offering additional tools.

The Most Authoritative Sites

Moz publishes the 500 sites with the highest DA scores: The Moz Top 500 Websites. For data reported below, I accessed the Top 500 list on May 29, 2022 – the list varies a bit from day to day.

It is not surprising that the top of the Moz 500 list has sites like Apple, YouTube, and Google, each scoring a perfect 100.

To get on the Moz Top 500 list you need a DA of at least about 92.

For each site, they give the number of linking root domains, more than 100,000 for all sites on the Moz Top 500 list, and in most cases more than 300,000. The sites at the top of the list have millions to tens of millions of different root domains linking in.

I downloaded the Moz Top 500 list and did an analysis by extension, obtaining the results shown below.


As expected, .com dominated, with 59% of the Moz Top 500 sites. Country codes are also well represented, accounting for 23.6%. There were substantially more .org, 42 sites, than .net, 14 sites.

I also looked at the country codes separately. I lumped second and first order, for example UK includes both and .uk, and similarly for AU and BR. The country codes with most sites are shown below.


Almost half, 43%, were from country codes not on the chart, but no individual country had more than 2 sites on the Moz Top 500.

The generic country code domain names that do well on the aftermarket were not much represented on the Moz list. There was only a single .co, one .tv and one .gg on the list. There were no .io, .ai, .cc or .vc sites at all on the Moz Top 500 list the day I checked.

Domain Companies High On Moz Top 500 List

Perhaps expected due to many incoming links, most of the major businesses in the domain world place very high in Moz DA ranking.

BrandBucket, Dan and Huge Domains all placed in the top 100 sites on the Moz Top 500 list, while Namecheap, Afternic, Sedo, BuyDomains and DomainMarket made the top 200. GoDaddy and Neustar, now owned by GoDaddy, also made the Moz 500 list.

Final Thoughts

Remember that both DA and DR are intended for rating developed websites, not simply domain names.

While DA and DR model how search engines like Google are expected to rank pages, Google, Bing and other search engines do not directly use the ranking data.

If acquiring domain names that have been developed, there are a wealth of other checks to perform, such as whether the domain name is on any blacklists for spam or malicious activity.

It is also wise to see how the domain name has been used in the past by browsing archived listings at the WayBack Machine.

Please feel free to share thoughts on the checks you do, either in evaluating websites you develop, or before acquiring names with a development past.
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The views expressed on this page by users and staff are their own, not those of NamePros.
Curious, what the relation between domain age and these rankings are?
I believe, based on what I read, domain age is one of the factors that Moz consider for DA, but that Ahrefs DR is based exclusively on the number and reputation of sites that link to the site.
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Top Contributor
Dan, Sedo, Afternic are in the top500 list. They don't deserve to be.
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It's a shame Alexa left us... RIP
Previously, I used a comprehensive analysis using four tools at once Alexa, Semrush, Ahrefs & MOZ
Thanks for the article.


Top Contributor
Anyone can block bots of authority ranking services. It's not very difficult. Then those services would show zero authority.
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