Domain Authority is a Flawed Metric

I have more conversations about SEO metrics than I’d like to.

Not because I don’t love talking about SEO, but because there are so many half-baked metrics and more so, half baked reasons for using them…

“But my time on site is so high”

One conversation I run into constantly has to do with top-level measures of domain/page competitiveness and authority.

Call me old school, but I do still like to know domain and page PageRank (PR)…


Because I think they are still relevant when used as barometer.

Even though PR hasn’t been updated since December 6, 2013, I think it still offers some direction for getting a general sense of a site’s established authority.

In that same vein, I look at Domain Authority (DA) and Page Authority (PA) with the same consideration.

It’s a relative measure that can be used as a directional metric – it’s not a pure play metric that you should be getting hung up on and it is ESPECIALLY not a metric that your clients should be obsessed with – or worse, track month over month as a signal of effective SEO.

What Is a Barometer Metric



  1. An instrument for measuring atmospheric pressure, used especially in weather forecasting.
  2. Something that registers or responds to fluctuations; an indicator

bar′o·met′ric(băr′ə-mĕt′rĭk), bar′o·met′ri·cal adj.

bar′o·met′ri·cal·ly adv.

ba·rom′e·try n.

For the purposes of this discussion I’m speaking specifically to definition #2; something that registers or responds to fluctuations; an indicator.

This is the important distinction.

This is also where Domain Authority is powerful.

As an indicator it is great in providing relative measures to assess both rank potential and downstream link equity.

Where There’s Ambiguity

The idea of using DA to gauge continuous improvement and “effectiveness of SEO” in the short-term is a recipe for disaster – where disaster is simultaneous frustration on both sides of the SEO table; from both clients and SEO providers.

Domain Authority is updated, at best, on a monthly basis furthermore – it’s really important to understand what the Mozscape index contains. Mozscape is a collection of URL’s that MOZ crawls and designates as fitting to be included in their index.


It IS a representative sample of trusted URL’s, chosen by MOZ.

It IS NOT a comprehensive collection of all URL’s that Google trusts, and uses to assess link value.

For this reason Mozscape link data should not be used as the sole source to:

  1. Track progress on link building campaigns.
  2. Report on month over month changes to SERP landscapes.
  3. Assess link velocity and determine rank potential timelines.

What’s actually been found here is that – none of the link graph tracking tools are sufficient, on their own.

But when used in concert together, you can start to get a more accurate representation of what’s going on.

As reported on in this sample study by Alexander Albuquerque, MOZscape had less that 10% of the total identified links when compared to Majestic and Ahrefs.


This study looked at link data from only 1,000 websites, looking at a max of 50,000 links per site for a total sample of 150,000,000 links – and while that may sound like a lot, relative to the internet; it’s not.

However, in my own personal experience I’ve seen similar patterns with MOZ missing the boat on reporting on large populations of links.

This really only becomes an issue if you’re leaning on MOZ to track progress on your link campaigns; since MOZ has such a small sample of sites – if you’re in any tangential or niche vertical not currently on their radar, new (and often powerful and important links) will not be counted or seen.

Another Weakness

MOZ, while certainly not a static index – is not truly dynamic either, in that updates don’t happen in real-time (or even near real-time for that matter).

So if you’re using MOZ for rank tracking you may be missing the boat on accurately reporting on the true fluctuations that are happening in the SERP’s.

Furthermore, because Mozscapedoes not track links it does not include and therefore crawl, it cannot be used to track link velocity and decay – critical measures in assessing and scoring rank potential for target keywords.

Using The Right Tool For The Job

Building organic rankings is a process I often analogize as being very similar to constructing a building; you have the foundation, the supports, scaffolding, and then all the floors on top.

In the same way a hammer and nails wouldn’t be useful for pouring your concrete foundation, you need to use the right data to design and operate your SEO campaigns.

Once you’ve completed your keyword research and the process of compiling your competitive data to carve out your priority list – here’s how I recommend moving forward:

  • Use a tool like Linkody to track new linking domains to your link building campaign targets as they come in.
  • Use Serpwoo to track SERP volatility and gain insight into which rankings have the greatest day of day and week over week fluctuations.. This can often operate in parallel with your other research to quickly, visually aid you in identifying opportunities to crack into new SERPs.
  • Use Ahrefs to track on-going link velocity and keep tabs on new links as they come in, opposed to Linkody, this is a report I would run weekly and monthly for macro level updates on link building effectiveness – and to show new LRD’s as they’re acquired.

The reason I recommend doing this specifically in conjunction with using Linkody is Ahrefs will help you build a sense of your “net new links” opposed to Linkody which will show you gross figures on new/lost links, some of which may drop off, get removed, who knows and not count toward your total rolling link equity.

How I Use Domain Authority

With all that said, it might sound like I’m hating on DA – which I promise you is not the case.

I still use DA on a daily basis, but I use it for what it’s good for; directional measurement and planning.

For tracking against the following activities DA and PA are my preferred metrics:

  1. Snapshot quantification of SERP-specific rank potential
  2. Top-level qualification of new link opportunities
  3. Initial evaluation of websites for acquisition

Snapshot Quantification of Rank Potential

For this example I’m going to dissect the U.S. SERP for a product query. This is non-personalized (logged out), incognito, and includes 3 PLA’s and then image results, both of which I’ve removed for the purposes of this discussion.

The keyword is 22″ wheel spacers.


OK so lot’s to talk about in these results – I intentionally picked a SERP that contains a curious occurrence I’ve been seeing in more and more product results where the first option is the product on Amazon.

So if you examine the domain authority for each of these 9 results, you’ll notice that the lower maximum is 17 in position #7 (which we’ll come back to in a moment), but that there’s a DA18 ranking in position #3 right after YouTube.

If you look a bit closer you’ll notice that the site that’s ranking, that based on DA alone shouldn’t be ranking, is the manufacturer’s site of the product listed on Amazon, and more so the domain is the manufacturer’s brand (ICHIBA).


I’ve been seeing this more and more on product SERP’s, where it seems Google is giving preference to the manufacturer’s product pages even if they are comparatively weaker.

If you’re wondering what those percentages are that I’ve listed for each result they are the computed “link diversity ratio,” or the percentage of links that come from unique linking root domains.

Often times when I see sites ranking with much lower DA, they tend to have a much stronger ratio of linking root domains versus their competitors.

Both domains in this SERP with the lowest DA have the highest diversity ratios.

What also strikes me about this SERP is that it seems Google is still testing the keyword intent. It does show PLA’s, so G does consider this a commercial query, however considering there is a YouTube result, and 3 forum results – it seems they are still testing the potential for informational intent on this keyword.

Again, just keep in mind that the link counts we’re seeing are those driving the calculation of these sites DA/PA since they are only links from within the Mozscape index.

Based on all the results above I think the rank potential for this SERP is position 3 or 4; if you had a site with a DA18+ and were willing to build even 4 links to the page I think you could easily crack this SERP.

Top-level Qualification of New Link Opportunities

Continuing the discussion that domain authority as a barometer is extremely useful, in addition to flow-through metrics like Citation Flow (CF), Trust Flow (TF), and Topical Trust Flow (TTF), we still run our link building campaigns using DA as a qualification metric.


So for instance, if we’re designing a new link building campaign for an Ecommerce client with the goal being to increase net new linking root domains, the first qualifier we look at is a base DA, likely 30+.

This helps us put a value on the links and time we will spend building our target list, as well as create priority buckets for which sites and contacts should get a bit of extra love during the outreach phase.

Initial Evaluation of Websites for Acquisition

When buying websites for the purposes of SEO there’s a few considerations depending on your plans for the site. In general the most common uses are:

  1. Operate the site as a stand-alone entity, maintaing its existing content, rankings, and audience
  2. Fold in the website’s content, re-direct in the domain, and absorb all current rankings and traffic, or
  3. Re-direct in the top-level domain (TLD) to an existing website to absorb the full range of the link and trust signals.

For the purposes of this example I’m looking at scenario #3.

MOZ claims that when you use a 301 redirect from one domain to another that it passes ~90% of the re-directing site’s link equity.

But how does this affect net domain authority?

In my personal experience, I tend to see 10% to 12% of the domain authority from the site being re-directed into the final destination site get transferred to the final site; so if you’re re-directing in a DA45 site, you might expect to see a DA boost of ~5 points.

Understanding Domain Authority

DA is a logarithmic measure between 0-100, so one way to conceptualize this is looking at in terms of a percentage scale, like 0% to 100%, where 100% represents the most trusted websites on the internet like Facebook, Amazon, and of course, Google.

The logarithmic nature means that it’s going to get harder to increase your DA as it increases; and that these increases will become exponentially harder as you move through the curve.


So it’s going to be easier in terms of time, links, and trust to move from a DA of 10 to 20 then it will be to go from 20 to 30.


Domain authority is a powerful, directional measure of trust and authority – but in cannot be used in a vacuum. There are other link strength and contextual signals that need to be considered to get a full picture of a domain’s ability to move the needle, rank on it’s own, or prop up other pages for rankings.

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  1. Nice post Nick.

    One other common issue I find is that people forget that their DA is always relative to other sites.

    Site owners will often freak out when their DA drop by a few points without realising that this is often only an indication of how their site compares to DA 100 sites, not to their direct competitors.

    1. Thanks Danny.

      That’s actually a fantastic point that I should probably add into this post as it’s happened to me several times. Site owners use DA as their single top-level metric to measure success and when/if it goes down they panic and suddenly question the effectiveness of all of their SEO campaigns.

  2. I know you said you aren’t hating on DA, but I am, but with reason.

    If you were to compare the company size of Moz vs the likes of Majestic & Ahrefs, you’ll see a VERY big difference, in both funding, resources and staff.. This should all result in Moz’s ability to be able to out-scale both Majestic & Ahrefs when it comes to their index size – I realize Majestic are solely focused on links, but Ahrefs (which is relatively still new to the industry) has been pumping out new, exciting tools like there’s no tomorrow that are all data-backed from different sources.

    Moz has always been behind Majestic when it comes to links, both in quantities and (which is the most crucial part) freshness – They still to this day don’t seem to have a solid freshness update in place to show users new links within their old links.. It requires you to look at / export data from TWO tabs if you want to see the most up-to-date data, which is intrinsically annoying for any user to have to do.

    Step up your game Moz, or you’ll be left behind by the Europeans that are currently battering your user base with better data.

    1. I agree with the notion that from an investment perspective, paying specific attention to both technology and technical resources, that you would expect more from MOZ in terms of building an industry-leading index OR to your other point, at least doing one thing in the space really well.

      In that same vein though, it does seem like for a very long time they were plagued with some major technical debt that, at least from the sounds of it, really hampered their ability to keep up at scale and run efficiently enough to grow at the pace of their competitors – not to mention routine production issues, that just seem to continue to bother users.

      1. Totally agree, but they’re all company mistakes that could of been changed – I think the problem is, they wanted to do things so far into the future for what they had, they ended up just hurting their overall technology.

  3. I agree that DA isn’t the golden metric of SEO, but it is a good reference point. In my experience, DA is one of the best overall metrics of a site’s ability to rank compared to the other leading link explorers. With that being said, when i’m looking to get a more holistic view of links, i’d much rather use AHREFs or Majestic compared to Moz, simply becasue of the breadth of their indicies are so much larger.

    1. I completely agree that it’s a good reference point, and to the point I make in the post – I think it’s still very useful as a directional measure of trust and link authority.

      Based on the case study I liked to toward the middle of the post, I think the fact remains that you still need to use all of the “big 3” link indices in concert to get a relatively accurate view of any site’s link profile without access to Search Console.

    1. Thanks David.

      I couldn’t agree more, in my mind *Trust* comes first, *Relevancy* is a close second. Your Leo meme in that post says it all 🙂 and re-enforces exactly what i”m hitting on in this post; DA as a measurement is useful for directional measurement – but there are literally 1,001 other elements that are more important to drive success and results.

  4. Great post.

    Good illustration about how the number of referring domains is more important than the number of links.
    I wonder though, although results #3 and #7 have a higher link diversity ratio, their respective number of RD of 19 and 20 are still a lot lower than the other results. It makes sense to be that high for #3 because it’s the manufacturer domain. But what about #7?

    1. They are very low, but if you’re going to draw inferences about this SERP, as low as the total number of LRD’s *is* for #7, I would also point out that the LDR (link diversity ratio) is exponentially higher.. and while there’s no hard and fast rules in SEO that always remain true, more times than not when there’s an outlier URL in a SERP the LRD tends to be a leading indicator.

  5. Hi,

    I am Linda, I own number of websites and I have hired people for SEO of all those sites, but Lately I myself learning something about technical stuff, which can help me handle my site son my own and latest i learned about Domain Authority and I have been working on it in past few months.

    But despite having good internal Linking and god content, Most of my sites Domain Authority is around 15-20 which I think is not good, as I love to attract more advertisers and without having Good Domain Authority, it is tough to attract high paying advertisers.

    So, what basically, I want to ask here, is there any way to increase Domain Authority quickly, I mean in 2-3 Months?

    ~ Linda

    1. Hey Linda –

      What are you doing to earn strong authority links from other websites? From just a quick look at your best steam irons website it’s clear you are putting time and effort into creating content, but the English is broken and there are numerous grammatical errors. This causes for problems for 2 immediate reasons;

      1. Google is very good at parsing natural language, and it’s immedaitely identifiable that the English on your sites is not native, and could be taken as machine-driven or spun content.
      2. In my experience webmasters and site owners are hesitant to link out to sites with spelling and grammar mistakes, so this could be directly impeding your ability to earn links.

  6. Nice article Nick.

    I rely on DA a bit too much when doing competition research. It’s probably the #1 metric I look at. I think it’s just easy to quickly look at DA to get a split second opinion of how authoritative a site is although there is A LOT more to consider than just that metric.


  7. Indeed a great post about domain authority.

    Domain authority is the most popular website metric developed by Moz. It is said that If the Domain authority of any site is high then that site will perform better in search engines and will gain more traffic.

    Domain authority help us to determine to quality of a site.

    To improve domain authority, We must have to gain quality backlinks and should must have to maintain the content quality on our website.

    Having high DA helps a lot while ranking any content in SERPs.

    I am glad that you have covered detailed article on it. Thanks for sharing it with us. 😀

  8. Thanks for the great post.

    Let’s say you need to analyse 1000 domains what’s the best way to do it when focussing on the relevancy of links pointing at those domains?

    I can only do this manually, which is a pain but hoping you have a better way of filtering it.


  9. Great break down on DA, i been trying to increase DA to my website (Forever) the right way, i think; i have to many links that are no follow, so i’am not seeing a increase in DA, but thanks for some great knowledge, it was needed

  10. Your right about DA not being the right tool for looking at links. I’m currently using ahrefs and they blow them out the water. A huge increase in available data outperforming everyone.

    You can also check all new links found. See whether you are getting hit by some unscrupulous jealous fellow webmaster.

    Thanks for the post Nick

  11. Great article,
    I have increased my knowledge. But i’m not agree that DA or PA 100% working. It’s all game about Link Quality. I have seen my many competitors who have Just DA 10 and beating a DA50’s domain with High Quality Backlinks.

    Majestic, MOZ and ahrefs are software or bots who scrape sites and it’s all data. So i suggest that we need to think our self.

  12. I gathered Good Information on Domain Authority Today.
    Thank you for sharing this blog. According to the latest update on Moz, I have noticed that if you’re posting a new blog that PA by default is 1. It used to happen on web 2.0 but it happening in blogs as well.

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