Moz DA (Domain Authority) Explained

Domain Authority (DA) is a metric developed by Moz to measure a site’s backlink profile and assess how well the site ranks on search engines.

Moz is the first tool to develop the domain authority metric. They were the pioneers. Soon, other SEO tools followed it up with their authority metrics like – Semrush AS, Ahrefs DR, and Majestic TF.

Here are the years when these authority metrics were introduced:

Authority Metric	Year of Introduction
Moz DA (Domain Authority)	2004
Majestic TF (Trust Flow)	2012
Ahrefs DR (Domain Rating)	2016
Semrush AS (Authority Score)	2018

So, let’s dive into the first authority metric ever introduced – Moz DA.

What Is the Moz DA (Domain Authority)?

Moz DA is an SEO metric measuring a site’s backlink strength. DA is developed by Moz to predict how well the site can rank on search engines.

In Moz’s own words:

“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.”

The higher the DA, the higher the site’s backlink strength. 

You can check a site’s Moz DA for free from here.

Enter the website name and Moz will provide you with the DA.

You will get the Domain Authority score along with the number of referring domains, ranking keywords, and spam score.

DA is measured on a logarithmic scale. What this means is – increasing DA gets tougher as you move to a higher score. For example, increasing DA from DA 10 to DA 12  is far easier than improving from DA 80 to DA 82.

That’s why hundreds of millions of websites have a DA of below 10, but only a few hundred have a DA near 100.

In addition, the score is measured on a relative scale from 0 to 100, with the latter being the strongest.

The relative scale here means that your site’s DA depends on other sites’ DA as well. 

Even if your site’s backlink strength has remained the same but other sites have improved their backlink profile – your DA can still go down.

How Is the DA Calculated?

Moz DA started as a measure that is completely based on links. It evaluated the number of linking root domains (referring domains) and the total quantity of links.

However, since 2019, Moz has changed its calculation methodology and has incorporated multiple factors. They also use a machine learning algorithm now to best-fit their DA metric to the site’s appearance in search results.

While the exact calculation is not public, Moz hints their main factors for DA include:

• Quantity of links
• Number of linking root domains (referring domains)
• Spam score
• Link quality

Both spam score and link quality, along with several other factors, were included in the DA calculation in 2019. Moz calls this new update – DA 2.0.

The new DA calculation uses these factors in a machine-learning model. The model predictively finds the “best fit” algorithm that correlates with Google rankings. 

While Moz has included more and more factors to detect spam signals, we have found that it’s not robust yet. Which brings us to the next section.

Moz DA Can Be Manipulated

A high DA score doesn’t mean much. A site with a high DR does not guarantee high traffic. We will show you this example at the end of this section.

Put simply, DA in isolation has no value. Plus, Moz DA can be manipulated.

In fact, there is an industry of freelancers ready to inflate your site’s DA.

We did a study on DA manipulation. The study is detailed here in case you want to deep dive into it.

The simplified version is: We contracted five Fiverr freelancers who are “authority hackers” to inflate five new domains.

The freelancers bundled their service to inflate these authority metrics – Ahrefs DR, Moz DA, and Majestic TF. Surprisingly the bundle didn’t include Semrush AS (we have discussed why in this article).

After two months, these were the results from the “authority hackers”:

As you can see, while Ahrefs DR is the most easily manipulated metric, Moz DA doesn’t fare well either. Moz DA is susceptible to tampering as well.

With the right “Authority hacker”, the moz DA score can be manipulated. And we did that with one domain. A DA of 52 for $80. 

As of 4 April 2024, the test domain still has a DA 52 according to Moz.

A key thing to note here is – the site doesn’t rank at all. 

Even Moz says so – that the site has zero ranking keywords. 

That’s how easily DA can be manipulated and why you should not trust the DA metric. 

What Is a Good DA Score?

A good Domain Authority score is when your site’s DA is higher than your competitor sites, assuming the DAs aren’t manipulated.

As a standalone metric, DA does not say much. It’s a vanity metric. It is useful only when you compare it with other sites. Especially the sites you are competing with.

For example, a site with a DA of 10 might still find it tough to rank on Google when most of its competitor sites have a DA of 40+.

Think about your chances for the keyword “weight loss”. All the top-ranked sites have a Moz DA score of 90+. Even if your site has a DA 40 score, you might find it tough to rank.

Similarly, a DA 20 site might rank easily when all of its competitors have a DA of less than 10.

Again, a high DA does not guarantee high traffic. It can be used as a proxy metric. But not as an absolute metric.

Wrapping Up

Moz DA has its uses. They were the pioneers of the domain authority metrics. DA can help when you use it to compare sites as long as the DAs aren’t manipulated.

However, DA in isolation doesn’t mean much. High DA doesn’t necessarily mean high traffic. And it is also susceptible to manipulation. In short, DA can be a fair metric if it is used to measure the progress of an exact website and assuming it wasn’t tampered with. It could be dangerously misleading if manipulated to sell the site or its backlinks.