Semrush AS (Authority Score) Explained

Authority Score (AS) is Semrush’s measure of a site’s quality and backlink strength. It is similar to other domain authority metrics like Ahrefs DR, Moz DA, and Majestic TF.

But unlike these other metrics, which focus entirely on backlinks, Semrush AS also factors in organic traffic and spam factors.

It makes AS the most tamper-proof metric compared to rivals. Continue reading to learn how it works.

Now, let’s examine Semrush’s Authority Score metric, how it is calculated, and how it differs from other domain metrics. 

What Is the Semrush Authority Score?

Semrush Authority Score (AS) started as a measure of a site’s backlink profile.

Over time it has evolved into a measure of the site’s quality in Google’s eyes.

In Semrush’s own words:

“Semrush Authority Score is our compound metric used for measuring a domain’s or webpage’s overall quality and SEO performance. It’s based on a series of metrics that prove trustworthiness and authority.”

The higher the Authority Score (AS), the higher the site’s perceived quality and backlink strength.

You can check your site’s AS with a free tool on my website or from the Semrush site, but you must register and log in there.

Our Authority checker tool gives you the AS; you only need to enter the site name.

You will get your site’s Semrush AS, along with the number of referring domains, URLs, and total backlinks.

AS is measured on a logarithmic scale. This means that increasing AS becomes more challenging as you move to a higher score. 

For example, increasing AS from AS 1 to AS 3  is far easier than improving from AS 71 to AS 73.

As a result, hundreds of millions of websites have an Authority Score below 10, but only a few hundred have an AS near 100.

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

The relative scale here means that your site’s AS also depends on other sites’ AS. Even if your site’s backlink profile and rankings have remained the same but other sites have improved their performance – your AS can go down.

How Is the AS Calculated?

Semrush employs three main parameters to calculate the Authority Score:

1. Link Power
2. Organic Traffic
3. Spam Factors (Natural Profile)

Link power is still the biggest factor in Semrush AS score, followed by estimated organic traffic. Spam factors are used as a sanity check and are negative factors to weed out spam sites and sites with manipulated link profiles.

#1. Link Power

Link power measures the quantity and quality of the backlinks a site has. 

More precisely, link power is calculated based on the amount of referring domains (do-follow links) and the authority of these referring domains. A link from an AS 80 site carries more weight than a link from an AS 20 site.

Semrush has also improved its link power calculation by factoring in the domain category (or niche).

When a domain links to another domain in the same niche, the link has a higher relevancy when compared to a link from an unrelated niche. 

For example, if you own a site related to cars, a backlink from another car website is more relevant to your AS than a backlink from, say, a shoe website.

#2. Organic Traffic

Semrush also accounts for a site’s organic search traffic in its AS calculation.

This is a valuable factor since relying on backlinks alone can lead to manipulating the authority metrics easily – as seen from our study here.

Long story short, Authority Metrics from Ahrefs and Moz can be very high even for websites with no traffic and zero content. Semrush will never give such websites a high score. 

Site authority manipulation hinges on manipulating the backlink profile. We will show you an example below of how factoring in organic traffic helps Semrush to weed out link spam.

#3. Spam Factors (Natural Profile)

Semrush also checks for indicators of spam or manipulation in the site’s backlink profile.

The lower the spam indicators (i.e., higher the natural link profile), the better the Authority Score.

Here are the spam signals Semrush uses in their AS scoring:

• No organic rankings on SERPs 
• An unnaturally high % of do-follow domains 
• An imbalance between links and organic traffic
• Too many referring domains with the same IP address 
• Too many referring domains with the same IP network
• The presence of another domain with an identical backlink profile 

The AS will be reduced if Semrush detects any of these spam factors on a site.

For example, if a site has many backlinks but no organic rankings on SERPs, its AS will still be low. We were talking about this earlier, and we will show you the example next.

Semrush AS Cannot Be Manipulated Easily

Authority Score as a standalone metric, doesn’t mean much. But since Semrush factors in organic traffic and spam factors in the AS calculation, it holds well compared to similar metrics like Ahrefs DR, Moz DA, and Majestic TF.

In short, Semrush AS cannot be manipulated easily compared to other authority metrics from similar SEO tools. Here’s why:

• Semrush AS checks the backlink profile to calculate the website authority. This is in line with what Ahrefs DR, Moz DA, and Majestic CF/TF do.
• In addition, it checks whether the website ranks and gets traffic from Google. This is unique to Semrush AS. If the website has a good backlink profile but doesn’t rank on Google, AS will be below 10.
• It also evaluates the website’s referring domains. The quality and organic traffic of these referring domains acts as a spam check. If these referring domains don’t get any organic traffic, show signs of being part of PBNs, have over 90% do-follow links, and/or display other suspicious patterns, the Authority Score will drop below 10. If the profile is natural yet weak, AS will be below 30.

Semrush AS rewards sites with natural backlink profiles and high organic traffic.

With such a “compound” scoring, Semrush AS is difficult to tamper with, especially when compared to other “authority” metrics that rely solely on checking the site’s backlink profile.

We did a study on this. The research post is here if you want to dive deep into the study.

Here’s what we did: We contacted Fiverr freelancers who are “authority hackers” ready to inflate a site’s domain authority metric for as low as $15.

These freelancers offered to improve these metrics, often bundling Ahrefs DR, Moz DA, and Majestic TF inflation in the same service. It is interesting to note that no one is guaranteed to boost the Semrush AS score.

We tried negotiating with a few freelancers to boost Semrush AS. But no one agreed.

A few freelancers who were ready to try – didn’t have any proof to showcase, asked for several months, and quoted hundreds of dollars in costs. 

We went back to the “authority hackers” who promised the fastest results but didn’t guarantee for Semrush AS.

To boost these sites’ domain metrics, we hired five freelancers for five domains. We paid them $15 to $85 – $275 in total for five contractors, and we waited for two months.

Here are the results:

Key takeaways:

1. Ahrefs DR is the easiest to manipulate.
2. While Moz DA and Majestic TF are not as easily manipulated as Ahrefs DR, they still can with the right “Authority hacker”.
3. Semrush is the most reliable and tamper-proof authority metric. The AS cannot be inflated easily.

All the domains we tested have zero organic traffic. They don’t have any rankings in the SERPs. And yet they show a high domain authority on SEO tools – except for Semrush AS.

What Is a Good Authority Score on Semrush?

A good Semrush Authority Score is when your site’s AS is higher than your competitor sites.

Semrush AS on an absolute scale 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 an AS of 10 might still find it tough to rank on SERPs when most of its competitor sites have an AS of 40+.

Think about your chances for the keyword “insurance”:

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

Again, a high AS does not necessarily mean high traffic. It can be used as a proxy metric. But not the be-all and end-all metric.

Final Thoughts

Semrush AS is tamper-proof compared to rival metrics Ahrefs DR, Moz DA, and Majestic TF, which have all shown that they can be manipulated. 

This is because the AS calculation factors in the site’s organic traffic and spam indicators. As a result, I consider Semrush Authority Score the most reliable and tamper-proof domain authority metric on the market.