A Comparison of Domain Authority Checkers for Link Building

Should domain authority checkers be a part of your SEO toolkit?

A couple of years ago, I wrote about Moz’s Domain Authority and how it did not represent Google’s PageRank.

No third-party metric does.

We still like metrics, though, because they give us a quick method of determining how good a site may be for our purposes (which is almost always link building, for me).

It’s important to remember that domain authority must be viewed in conjunction with many other metrics.

What Are the Major Metrics We Use for Measuring Domain Authority?

Ahrefs Domain Rating

According to Ahrefs:

“Domain Rating (DR) shows the strength of a website’s backlink profile compared to the others in our database on a 100-point scale.”

DR is a relative term that takes into account the number of sites that link to you as well as how many other domains those sites link out to.

The higher the DR, the more link equity it will transfer to the domains that the site links out to. This equity is split equally so a site that only links out to 50 domains can be a bigger influence on its target domains’ DR than a site that links out to 500,000 domains.

Semrush Authority Score

This one is the latest entry into the domain authority metrics war.

According to Semrush:

“Authority Score is the result of calculations run by a neural network algorithm that uses machine learning to measure every domain’s authority based on quality, popularity, and backlink signals.”

Authority Score measures overall quality and SEO performance.

It takes into account factors such as the number of referring domains pointing to a site, the number of outbound links from each referring domain, follow vs nofollow links pointing to the site, etc.

Moz Domain Authority

This is commonly and mistakenly thought of as how authoritative Google views a website.

According to Moz:

“Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how likely a website is to rank on search engine result pages (SERPs). A Domain Authority score ranges from one to 100, with higher scores corresponding to a greater ability to rank.”

Majestic TrustFlow

Majestic TrustFlow is a little different from the others.

Majestic says:

“Trust Flow, a trademark of Majestic, is a score based on quality, on a scale between 0-100. Majestic collated many trusted seed sites based on a manual review of the web. This process forms the foundation of Majestic Trust Flow. Sites closely linked to a trusted seed site can see higher scores, whereas sites that may have some questionable links would see a much lower score.”

TrustFlow can also be broken down further than its one main number into topics which each have their own TrustFlow.

This measures how close your site is to the most trusted websites in specific categories such as Shopping, Arts, Business, Recreation, etc.

Comparing Domain Authority Checkers

For the purpose of this experiment, we’ll use some well-known and lesser-known sites.

As you can see, the first five sites have metrics that all look like they match up well enough. There aren’t any exceptionally low ones that stand out.

I imagine that readers recognize those sites, too. I think we’d probably all agree that they’re authoritative and that a link from them would be great.

The Punk News site is one that I chose because to me, it’s the most authoritative site on punk rock. It also has consistent metrics across the board.

Getting a link from it to your camping site probably won’t help you out much, though. You may get a rankings boost but you probably won’t get much traffic or many conversions.

If you’re selling camping supplies, this is probably not an authoritative site for your niche. If you’re selling vintage punk gig flyers, it would be.

The last two sites are personal blogs that I found doing some random searches.

The Life With Emily site has consistent traffic over the past two years and gets around 1500+ visits a month, according to Semrush. The site ranks well for search terms like “how to paint a front door.”

If I had a DIY client, I’d love a link on this site. I would think that it might send me some converting traffic and have authority for my client. It doesn’t have a DR 70 or a DA 65, but it has relevance.

The last site has lower metrics and very little traffic, so I probably wouldn’t seek out a link here. However, they seem to do a lot on social media, which might be more valuable to them due to the industry.

They seem to have a thriving business. They have real-world authority, and domain metrics can’t measure that.

Domain Authority Checkers Are Missing Real-World Context

I decided to take a look at some deindexed sites (I won’t reveal which ones, because I don’t like outing people).

I come across these sites when link sellers send me big lists. I’m curious about their metrics and wondering why someone wants to sell me a link for $40.

Site A is deindexed and has a DR 72, a DA 37, AS 52, and TF 21.

Site B is deindexed and has a DR 29, a DA 10, AS 25, and TF 21.

Both of those sites would be acceptable to most of my clients simply based on their metrics. Site A would be quite desirable for all of them.

But they aren’t indexed in Google, so the only way you’ll come across them is if you get to them from a link on another page, or you know the domain for some reason.

How authoritative do you think a site is if Google has removed them from their index?

Those deindexed sites also have zero traffic and that’s been the case for the last two years.

Have they been deindexed for two years? If so, how can they still look so good metrics-wise?

Since the metrics are good, I could easily get a link on either site and many clients would just see a DR 72 and probably be happy.

They’d have no idea that these links were practically worthless.

What Other Metrics Can Help Gauge True Domain Authority?

Traffic

A site doesn’t necessarily have to have amazing traffic to help you rank, but your odds of having people come to your site from a link increase drastically when there is more traffic.

Getting a link on a site with zero traffic probably won’t help you much, and there’s usually a good reason why a site has no traffic.

If a link on a site like that happened organically that would be fine, but I wouldn’t spend time pursuing one unless the reason it had no traffic was that it was brand new.

It’s normal to see some dips but in general, you want to see consistent or increasing traffic.

Referring Domains

A site that is widely linked to should theoretically be an authoritative site, but because links can be so easily manipulated I don’t think it’s that straightforward.

You certainly can’t just look at quantity over quality.

What you can do is look at the quality of those referring domains and check to see if they look like the kind of links you’d want for your client or website.

Rankings and Ranking Keywords

If a site ranks well for keywords that it should rank for, that’s a good sign.

Good rankings also increase the chance for more traffic to the site which in turn increases the chance to get more visitors to your site.

Metrics Are Only the Start of Determining Authority

It’s key to remember that none of these metrics comes from Google, although many people still think of Moz’s Domain Authority as being representative of Google’s PageRank.

Moz has stated that this is not true and they’ve tried to clear up the confusion but the misunderstanding persists.

If you want to use metrics to help gauge authority, I would suggest that you just pick one and use it for trending purposes.

I’ve used every one of these for various clients over the years, mainly because the client wanted to set a minimum metric for sites we’d get links on.

I like to have a good initial guideline for my team to use to start evaluating a site but definitely do not think any of these metrics should be used as the only data that makes you think a site has the authority you seek.

More Resources:

Image Credits

Image 4: Majestic
All screenshots taken by author, March 2021

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