A Comprehensive Analysis of the New Domain Authority

Moz’s Domain Authority is requested over 1,000,000,000 times per year, it’s referenced millions of times on the web, and it has become a veritable household name among search engine optimizers for a variety of use cases, from determining the success of a link building campaign to qualifying domains for purchase. With the launch of Moz’s entirely new, improved, and much larger link index, we recognized the opportunity to revisit Domain Authority with the same rigor as we did keyword volume years ago (which ushered in the era of clickstream-modeled keyword data).

What follows is a rigorous treatment of the new Domain Authority metric. What I will not do in this piece is rehash the debate over whether Domain Authority matters or what its proper use cases are. I have and will address those at length in a later post. Rather, I intend to spend the following paragraphs addressing the new Domain Authority metric from multiple directions.

Correlations between DA and SERP rankings

The most important component of Domain Authority is how well it correlates with search results. But first, let’s get the correlation-versus-causation objection out of the way: Domain Authority does not cause search rankings. It is not a ranking factor. Domain Authority predicts the likelihood that one domain will outrank another. That being said, its usefulness as a metric is tied in large part to this value. The stronger the correlation, the more valuable Domain Authority is for predicting rankings.


Determining the “correlation” between a metric and SERP rankings has been accomplished in many different ways over the years. Should we compare against the “true first page,” top 10, top 20, top 50 or top 100? How many SERPs do we need to collect in order for our results to be statistically significant? It’s important that I outline the methodology for reproducibility and for any comments or concerns on the techniques used. For the purposes of this study, I chose to use the “true first page.” This means that the SERPs were collected using only the keyword with no additional parameters. I chose to use this particular data set for a number of reasons:

  • The true first page is what most users experience, thus the predictive power of Domain Authority will be focused on what users see.
  • By not using any special parameters, we’re likely to get Google’s typical results.
  • By not extending beyond the true first page, we’re likely to avoid manually penalized sites (which can impact the correlations with links.)
  • We did NOT use the same training set or training set size as we did for this correlation study. That is to say, we trained on the top 10 but are reporting correlations on the true first page. This prevents us from the potential of having a result overly biased towards our model.

I randomly selected 16,000 keywords from the United States keyword corpus for Keyword Explorer. I then collected the true first page for all of these keywords (completely different from those used in the training set.) I extracted the URLs but I also chose to remove duplicate domains (ie: if the same domain occurred, one after another.) For a length of time, Google used to cluster domains together in the SERPs under certain circumstances. It was easy to spot these clusters, as the second and later listings were indented. No such indentations are present any longer, but we can’t be certain that Google never groups domains. If they do group domains, it would throw off the correlation because it’s the grouping and not the traditional link-based algorithm doing the work.

I collected the Domain Authority (Moz), Citation Flow and Trust Flow (Majestic), and Domain Rank (Ahrefs) for each domain and calculated the mean Spearman correlation coefficient for each SERP. I then averaged the coefficients for each metric.


Moz’s new Domain Authority has the strongest correlations with SERPs of the competing strength-of-domain link-based metrics in the industry. The sign (-/+) has been inverted in the graph for readability, although the actual coefficients are negative (and should be).

A Comprehensive Analysis of the New Domain Authority

A Comprehensive Analysis of the New Domain Authority

Moz’s Domain Authority scored a ~.12, or roughly 6% stronger than the next best competitor (Domain Rank by Ahrefs.) Domain Authority performed 35% better than CitationFlow and 18% better than TrustFlow. This isn’t surprising, in that Domain Authority is trained to predict rankings while our competitor’s strength-of-domain metrics are not. It shouldn’t be taken as a negative that our competitors strength-of-domain metrics don’t correlate as strongly as Moz’s Domain Authority — rather, it’s simply exemplary of the intrinsic differences between the metrics. That being said, if you want a metric that best predicts rankings at the domain level, Domain Authority is that metric.

Note: At first blush, Domain Authority’s improvements over the competition are, frankly, underwhelming. The truth is that we could quite easily increase the correlation further, but doing so would risk over-fitting and compromising a secondary goal of Domain Authority…

Handling link manipulation

Historically, Domain Authority has focused on only one single feature: maximizing the predictive capacity of the metric. All we wanted were the highest correlations. However, Domain Authority has become, for better or worse, synonymous with “domain value” in many sectors, such as among link buyers and domainers. Subsequently, as bizarre as it may sound, Domain Authority has itself been targeted for spam in order to bolster the score and sell at a higher price. While these crude link manipulation techniques didn’t work so well in Google, they were sufficient to increase Domain Authority. We decided to rein that in.

Data sets

The first thing we did was compile a series off data sets that corresponded with industries we wished to impact, knowing that Domain Authority was regularly manipulated in these circles.

  • Random domains
  • Moz customers
  • Blog comment spam
  • Low-quality auction domains
  • Mid-quality auction domains
  • High-quality auction domains
  • Known link sellers
  • Known link buyers
  • Domainer network
  • Link network

While it would be my preference to release all the data sets, I’ve chosen not to in order to not “out” any website in particular. Instead, I opted to provide these data sets to a number of search engine marketers for validation. The only data set not offered for outside validation was Moz customers, for obvious reasons.


For each of the above data sets, I collected both the old and new Domain Authority scores. This was conducted all on February 28th in order to have parity for all tests. I then calculated the relative difference between the old DA and new DA within each group. Finally, I compared the various data set results against one another to confirm that the model addresses the various methods of inflating Domain Authority.


A Comprehensive Analysis of the New Domain Authority

A Comprehensive Analysis of the New Domain Authority

In the above graph, blue represents the Old Average Domain Authority for that data set and orange represents the New Average Domain Authority for that same data set. One immediately noticeable feature is that every category drops. Even random domains drops. This is a re-centering of the Domain Authority score and should cause no alarm to webmasters. There is, on average, a 6% reduction in Domain Authority for randomly selected domains from the web. Thus, if your Domain Authority drops a few points, you are well within the range of normal. Now, let’s look at the various data sets individually.

A Comprehensive Analysis of the New Domain Authority

A Comprehensive Analysis of the New Domain Authority

Random domains: -6.1%

Using the same methodology of finding random domains which we use for collecting comparative link statistics, I selected 1,000 domains, we were able to determine that there is, on average, a 6.1% drop in Domain Authority. It’s important that webmasters recognize this, as the shift is likely to affect most sites and is nothing to worry about.

Moz customers: -7.4%

Of immediate interest to Moz is how our own customers perform in relation to the random set of domains. On average, the Domain Authority of Moz customers lowered by 7.4%. This is very close to the random set of URLs and indicates that most Moz customers are likely not using techniques to manipulate DA to any large degree. 

Link buyers: -15.9%

Surprisingly, link buyers only lost 15.9% of their Domain Authority. In retrospect, this seems reasonable. First, we looked specifically at link buyers from blog networks, which aren’t as spammy as many other techniques. Second, most of the sites paying for links are also optimizing their site’s content, which means the sites do rank, sometimes quite well, in Google. Because Domain Authority trains against actual rankings, it’s reasonable to expect that the link buyers data set would not be impacted as highly as other techniques because the neural network learns that some link buying patterns actually work.

Comment spammers: -34%

Here’s where the fun starts. The neural network behind Domain Authority was able to drop comment spammers’ average DA by 34%. I was particularly pleased with this one because of all the types of link manipulation addressed by Domain Authority, comment spam is, in my honest opinion, no better than vandalism. Hopefully this will have a positive impact on decreasing comment spam — every little bit counts.

Link sellers: -56%

I was actually quite surprised, at first, that link sellers on average dropped 56% in Domain Authority. I knew that link sellers often participated in link schemes (normally interlinking their own blog networks to build up DA) so that they can charge higher prices. However, it didn’t occur to me that link sellers would be easier to pick out because they explicitly do not optimize their own sites beyond links. Subsequently, link sellers tend to have inflated, bogus link profiles and flimsy content, which means they tend to not rank in Google. If they don’t rank, then the neural network behind Domain Authority is likely to pick up on the trend. It will be interesting to see how the market responds to such a dramatic change in Domain Authority.

High-quality auction domains: -61%

One of the features that I’m most proud of in regards to Domain Authority is that it effectively addressed link manipulation in order of our intuition regarding quality. I created three different data sets out of one larger data set (auction domains), where I used certain qualifiers like price, TLD, and archive.org status to label each domain as high-quality, mid-quality, and low-quality. In theory, if the neural network does its job correctly, we should see the high-quality domains impacted the least and the low-quality domains impacted the most. This is the exact pattern which was rendered by the new model. High-quality auction domains dropped an average of 61% in Domain Authority. That seems really high for “high-quality” auction domains, but even a cursory glance at the backlink profiles of domains that are up for sale in the $10K+ range shows clear link manipulation. The domainer industry, especially the domainer-for-SEO industry, is rife with spam.

Link network: -79%

There is one network on the web that troubles me more than any other. I won’t name it, but it’s particularly pernicious because the sites in this network all link to the top 1,000,000 sites on the web. If your site is in the top 1,000,000 on the web, you’ll likely see hundreds of root linking domains from this network no matter which link index you look at (Moz, Majestic, or Ahrefs). You can imagine my delight to see that it drops roughly 79% in Domain Authority, and rightfully so, as the vast majority of these sites have been banned by Google.

Mid-quality auction domains: -95%

Continuing with the pattern regarding the quality of auction domains, you can see that “mid-quality” auction domains dropped nearly 95% in Domain Authority. This is huge. Bear in mind that these drastic drops are not combined with losses in correlation with SERPs; rather, the neural network is learning to distinguish between backlink profiles far more effectively, separating the wheat from the chaff.

Domainer networks: -97%

If you spend any time looking at dropped domains, you have probably come upon a domainer network where there are a series of sites enumerated and all linking to one another. For example, the first site might be sbt001.com, then sbt002.com, and so on and so forth for thousands of domains. While it’s obvious for humans to look at this and see a pattern, Domain Authority needed to learn that these techniques do not correlate with rankings. The new Domain Authority does just that, dropping the domainer networks we analyzed on average by 97%.

Low-quality auction domains: -98%

Finally, the worst offenders — low-quality auction domains — dropped 98% on average. Domain Authority just can’t be fooled in the way it has in the past. You have to acquire good links in the right proportions (in accordance with a natural model and sites that already rank) if you wish to have a strong Domain Authority score.

What does this mean?

For most webmasters, this means very little. Your Domain Authority might drop a little bit, but so will your competitors’. For search engine optimizers, especially consultants and agencies, it means quite a bit. The inventories of known link sellers will probably diminish dramatically overnight. High DA links will become far more rare. The same is true of those trying to construct private blog networks (PBNs). Of course, Domain Authority doesn’t cause rankings so it won’t impact your current rank, but it should give consultants and agencies a much smarter metric for assessing quality.

What are the best use cases for DA?

  • Compare changes in your Domain Authority with your competitors. If you drop significantly more, or increase significantly more, it could indicate that there are important differences in your link profile.
  • Compare changes in your Domain Authority over time. The new Domain Authority will update historically as well, so you can track your DA. If your DA is decreasing over time, especially relative to your competitors, you probably need to get started on outreach.
  • Assess link quality when looking to acquire dropped or auction domains. Those looking to acquire dropped or auction domains now have a much more powerful tool in their hands for assessing quality. Of course, DA should not be the primary metric for assessing the quality of a link or a domain, but it certainly should be in every webmaster’s toolkit.

What should we expect going forward?

We aren’t going to rest. An important philosophical shift has taken place at Moz with regards to Domain Authority. In the past, we believed it was best to keep Domain Authority static, rarely updating the model, in order to give users an apples-to-apples comparison. Over time, though, this meant that Domain Authority would become less relevant. Given the rapidity with which Google updates its results and algorithms, the new Domain Authority will be far more agile as we give it new features, retrain it more frequently, and respond to algorithmic changes from Google. We hope you like it.

Be sure to join us on Thursday, March 14th at 10am PT at our upcoming webinar discussing strategies & use cases for the new Domain Authority:

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Citation Factor, Trust Factor And How They Relate To Domain Authority

They actually don’t relate to Domain Authority.  Domain Authority is a metric designed by Moz to help replace Google’s Page Rank which used to be made available to the public but has since been discontinued or at least the public portion is no longer available.  Now Moz isn’t the only company offering a replacement to Page Rank, Majestic came up with Citation Factor and Trust Factor.  You’d expect these two still somewhat relate to each other as they in theory are meant to portray the same thing but they rarely do.  This leaves it up to you to decide which metric to use to determine a site’s ability to rank a page on Google.

This is a second part to the Domain Authority post I recently made.

Moz And Majestic Disagree A lot

This is worth a separate post and it will be but for now just noting some random stats on domains in this spreadsheet do you see DA CF or TF rising and falling together?  BTW this spreadsheet is so unSEO friendly and will likely never get ranked for mobile, so I may have to wipe it out of a mobile version which is a shame.

For instance notice two domains are a DA 29 … the CT and TF are totally different.  Or DA 46 We have 6 all right next to each other, the CT ranges from 31 to 0 and TF ranges from 0 to 10 so no correlation on these really.  So now we know they are supposed to express the same thing but wildly disagree…what are Citation Flow and Trust Flow then?

Citation Flow

Citation Flow

Citation Flow is Majestic’s attempt at forecasting the influence of a site…what its capable of making folks do or believe.  This has nothing to do with how valid the argument or evidence is just the ability to be noticed.  I like to think of the Kardashians, Id argue they have influence and they can get noticed.  That being said I’m not saying they should be or that what they believe or think is valid or worthy of listening too.

I honestly don’t use this metric, I largely feel it irrelevant.  Its okay to watch…ever seen the movie Airplane! … Citation Flow is the guy who says nothing useful but is funny.

Trust Flow

How authoritative and trust worthy is the content they produce is the question Trust Flow tries to address.  Back to the Kardashians … I would assume that they have influence but trust in what they say isn’t all that great.  They are not experts at much.  Looking up one of their “personal” sites we have a TF of 21.  21 of 100 isn’t huge, its kinda high when we think of all the sites out there but I tossed in Neil Patel and Moz (TF competitor site) and they did well.  Patel 51 and 62 to Moz.  Which I can believe that Kim’s site is a 21 to those other sites being more than double in trustworthy content.

Some sites are used as seed trustworthy sites.  So lets say harvard.edu is trustworthy so we’ll give them a 100 ( not saying they have a 100 ) then who they link to we give a 90.  Who the 90s link too we give an 80, TF is kinda how far away a site is linked to a known trusted source.

I do personally use this metric but I give a lot of credit to very low numbers.  So If something is a 8 or 10 in TF I consider them at the start of trustworthiness like a 15 is average…seeing Moz at 61 is likely near God’s level of trustworthiness.

So that’s a high level look at Citation Flow ( Basically Useless ) and Trust Flow ( Generally Good ) and how they relate to Domain Authority ( no relation at all)

They’re competing products by two companies attempting to guess what Google thinks of your site…and they aren’t 100% accurate…

How I Use Metrics To Determine SEO Value

I use them as a mixture of fact and fiction, I look at DA first and foremost.  I’ve never seen a DA 0 With a CF 100 and TF 100 and if I did I wouldn’t have thought “that’s a good site”.  So DA is the first thing that attracts my attention.  I’ve seen plenty of DA 50 with a CF 14 and TF 12 and thought, this one is worth more review.

A secondary indicator of SEO value to me is then TF but I lower the bar on TF, I’ll make another post on this later, how I use these numbers to determine SEO value.

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What Is Domain Authority Why Should I Care?

Domain Authority is in my opinion the single greatest indicator of a sites ability to compete organically for search traffic.  It is a great question and its simply complex.  Keep in mind Domain Authority or DA as we shall refer to it pretty much here on is the single best number to predict ranking ability and we know that the top 3 positions consume over half of all searches so it can be directly attached to traffic.

A few disclaimers: Domain Authority is not a Google creation it is from Moz.com and it is their educated guess at how Google see’s your authority.  But it is not Google’s so remember that.  Secondly I am going to go over this in a higher level and use some half truths for simplicity.  If you want the whole truth just read the articles or Google the topics discussed for greater detail.  Finally, most of what I will show you are other people’s guesses as to what goes into Moz’s Domain Authority which again is a guess about Google’s metric on a site.  Google doesn’t tell us exactly and they shouldn’t, Moz doesn’t tell us either because they want you to pay for it.  Moz isn’t the only one guessing, a lot of folks guess and some include Majestic’s Citation Factor and Trust FactorSEOProfiler has it’s LIS.  For simplicity and since I’m the one running this show we’ll focus for now on Domain Authority by Moz.

Now it’s a simple number from 1 to 100 but it isn’t like a ladder with even steps, as you climb the steps get bigger and it takes more to gain a level.  So from DA 1 lets say you gain 5 backlinks and two are from sites that have a decent DA 40 and Moz bumps your score up to a DA 3.  If you gain 5 more links to your site and they also have similar metrics as the last bunch you might assume you’re set to have a DA 6, but you get surprised when it is reported as a 4.  Another set of 5 and it stays a 4.  DA levels are harder to improve the higher you get your site.

What Determines Domain Authority?


Domain authority is the best metric because it provides us with a single number but its based on some rather key and diverse factors.  Yes, it is backlinks but its so much more than that…but it is largely backlinks or incoming links from other domains.  These serve as citations, they’re references from other entities that acknowledge publicly that this site they are link too, yours is authoritative.  Coupled with “anchor text” or the words that make up a link that aren’t the address they can define a site.  More on that towards the end.  This is anchor text it has a link but the anchor text serves as the vanity description of the content at the other end of the link.  The link comes from another site to yours and depending upon that site’s authority the link is more or less powerful than another.

domain-authorityWe’ll talk in greater depth about SEO Backlinks but for now let’s just understand that backlinks are votes from other sites.  Not all backlinks are created equal.  The more backlinks the more authority, and one vote per site.  So 800 links from another site you own are not worth 25 from 25 sites.

In the graphic to the left links are the blue AND red slices of the pie and together they make up 49%.  The next biggest element is SOCIAL MEDIA MENTIONS.  I do that in all caps because I’ve always included social media as an element of reports I offer in client proposals and I get told often they don’t care about all that.  I just sit back and scribble down that they don’t know what they don’t know yet.

Social Media Mentions

Sure you need an account and you need followers but to get those followers you need to post regularly.  Five or Six times randomly during the year isn’t regular.  Thats why so many people feel social media doesn’t matter because they were unable to tap into the great interest on Facebook in their widgets.   News flash no one is really going to be interested in your widget but you and a handful of individuals.  Thats why your messages need to have more than just “buy our widget.”  If you are a church for instance a weekly devotional or prayer list is better than telling people to come on Sunday week after week.  The biggest mistake is not including a link to your site in your post.  While there may be a link off of your profile page to your site your message can be repeated by others and each repeat or share is from their profile. It may mention you and likely link back to your profile but that is still one link to your site.  Include a link.

social media mention with link

Domain Age Matters And It Should

So you’re going out there and you found a domain name thats available and you want to outrank your competition in a month.  SEOs laugh out loud around the globe…Highly unlikely, it’s partly you lack street cred.  I’d love to rank number one in the keyword Louisville SEO but I don’t.  I’m the 89.8th result.  MatthewLeffler.com is 352 days old as I am writing this.  The top result for Louisville SEO is 9 years and 207 days old.  Indirectly they’ve got 9 years worth of content, returning traffic and backlinks than I have and so they are given a bonus for that longevity.  Partly to prevent searchers from getting a completely different result every time a new domain picks a keyword.   Its easier though as you age, the difference between 5 yrs and 9 years is trivial and the distance between 1 day and 1 year is a stretch.  Sometimes buying an existing domain thats relevant to your business will give you a way around this, but you’re at the mercy of what is for sale and like a foster kid you don’t know about it’s past.

Brand Search Volume

Nobody said SEO was fair

Sometimes in SEO it feels like you’re swimming with Joan Crawford.  This one I feel is a bit much … brand search volume is how often people are looking for you.  Well isn’t that impossible until they know about me and the reason they don’t know about me is because you have me on page 4?  Couldn’t brand search volume arguably be covered in social media mentions and backlinks?  We’ll now that we got those out of the way, nobody ever said life was fair, Tina.

I’ve decided that I’ll figure out a way to sneak a reference to a favorite movie of mine into every post from here on.

But I digress, so your brand search volume does make sense to be included because people searching for Coca Cola do not want to see Pepsi.  I’m from deep Coke territory and even Taco Bell has stopped asking if I want a Pepsi.  So has Google it appears.

Incidentally I would suspect that local plays into this heavily.  Google knows where the searches are coming from so they understand the foot print of your business.  Which is why Googling the best landscaper in town is different in each town.  Food for thought if you build a regional powerhouse and expand into a new city.

Domain Authority Case Study – Project No Wire Hangers

Sorry I wont make this all about that movie but we all know …. NO Wire Hangers.  For our purposes hangers are domains and they can be wire or wooden.  Depending on the hanger or domain your attempts to rank for a keyword will be affected, like the clothes you hang on them.  I’ll show you several domains stats that I have built completely alone over several months.  It hasn’t been a dedicated effort so these numbers could have been better but the effort has been the same.  Some are older than others some are the same age. We’ll dissect these domains and metrics extensively.

Matt’s Project Hangers

URL Moz DA Moz PA MozRank External Links
seandelahanty.com 29 / 100 27 / 100 2.70 112
cloud502.com 28 / 100 24 / 100 2.40 134
votelouisville.com 23 / 100 19 / 100 1.90 4
matthewleffler.com 23 / 100 23 / 100 2.30 112
data502.com 22 / 100 21 / 100 2.10 12
matt2.info 20 / 100 16 / 100 1.60 51
seandelahanty.org 18 / 100 19 / 100 1.90 36
forbrent.com 16 / 100 11 / 100 1.10 0
countyattorney.info 14 / 100 10 / 100 1.00 0
seodata.cloud 12 / 100 16 / 100 1.60 11
chriscoffman.rocks 8 / 100 6 / 100 0.60 4

Feel free to look into them and make some assumptions.  You may find tools that I have discussed previously useful in “auditing” the domains.  Much like a Sciencetologist audits a person with toys and wild claims so does your SEO and look we have just about as many acronyms.  Now go and let your Thetan figure out where the keywords were in the graph.  Spoiler … anchor text that you had no control over … officially.  Here is a further reading on the power of anchor text…in 2004 “Miserable Failure” was George W. Bush’s Whitehouse biography page and no one optimized it for that.

Miserable Failure

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