Domain Authority: What It Is, What It Isn’t & Why It Matters

Ask a roomful of digital marketing professionals what domain authority is, and they’ll likely mention domain authority scores from companies like Moz or SEMrush. While these third-party domain scores can be helpful indicators of a site’s authority, it’s a common mistake to conflate them with the authority signals Google uses to rank content.

Domain authority (DA) is wrongly interpreted as a Google metric so often that it’s high time we do some serious myth-busting about what DA is. I want to set the record straight about what Google says about authority and talk about how search engines evaluate it.

Let’s get started.

What Is Domain Authority?

Domain authority, website authority, or site authority is a catchall term for the quality signals Google uses in its core algorithm. Rather than being a metric, it’s shorthand for a collection of signals that Google interprets as being common to authoritative websites. 

Many third-party SEO tools attempt to calculate a website’s domain authority and simplify it into a single metric or “score” that users can use to assess how Google interprets their site’s domain authority or the authority of a site linking to theirs. (Questions about authority often come up when we talk about backlinking).

The problem is, third-party metrics, like SEMrush’s Authority Score and Moz’s Domain Authority Score, use proprietary algorithms that are a best guess at the Google search algorithm.

Domain Authority is not a Google ranking factor and has no impact on a website’s performance in search. Third-party domain authority scores are comparative metrics rather than absolute metrics. That means they’re designed to compare the authority of one site against another as measured by a particular algorithm, which is a backward engineered, theoretical estimation of the Google Search algorithm.

The fact of the matter is that authority is a concept that can’t easily be measured.

There is no single metric that can represent the quality of a website. That’s why it’s best to use various indicators and analytics to determine a website’s potential to rank well in SERPs.

Domain Authority: A Trailing or Predictive Metric?

Another common misconception about domain authority scores is that they predict how well a site will perform in search results. In reality, third parties compile a proprietary DA score based on trailing metrics (also known as lagging indicators), which are past performance indicators. By comparison, predictive metrics (leading indicators) indicate future performance.

Because companies like Moz, Ahrefs, and SEMrush don’t have the massive infrastructure and resources that Google has, they have no choice but to base their domain authority scores on trailing metrics. So, regardless of how they frame it, their authority scores can’t predict a website’s future success — it’s more like a best guess based on a limited data sample of past performance indicators.

How Is Domain Authority Calculated?

Here are some examples of how different platforms calculate scores related to website or domain authority.

Moz Domain Authority, Explained

Moz’s tool allows businesses to check Domain Authority to “predict how likely a website is to rank on search engine result pages (SERPs).” Moz uses different factors to calculate this score based on a sample of links to a website or page. They also explicitly state that DA isn’t a metric Google uses to rank websites.

Moz has also developed a Page Authority scoring system to “predict” how well specific pages will rank on search engines. This tool generates scores using machine learning to identify algorithms correlated with rankings across thousands of SERPs.

Citation Flow & Trust Flow from Majestic

Majestic’s Flow Metric score is a domain score that incorporates their Citation Flow and Trust Flow algorithms. Trust flow measures the degrees of separation between any given website and a site Majestic has designated as a “trusted seed site.” Citation Flow tries to predict how influential a URL is based on how many other sites link to it.

Domain Rating from Ahrefs

Ahrefs’ Domain Rating score calculates the strength of a given domain based on the quality and quantity of inbound links (backlinks) a website has and the quality of those external links.

Authority Score from SEMrush

SEMrush’s Authority Score uses machine learning to calculate a site’s quality, popularity, and backlink signals based on organic search data, traffic metrics, and backlink gains or losses.

What Does Google Say About Domain Authority?

John Mueller has addressed this topic directly in the past, stating that Google doesn’t have a website authority score or anything like it.

However, Mueller said that Google uses sitewide signals to look at a website’s overall quality to rank new pages. Rather than using an official scoring system, Google looks at domain ranking signals based on a website’s current state rather than past performance or quality.

Time Out for Real Talk

At Victorious, we don’t take everything that John Mueller, Gary Ilyes, or any other “SEO expert” says as gospel. Instead, we put their statements into the context of our own experiences and data. Sometimes our data is consistent with what they say, and sometimes it’s not. This isn’t to say that they’re deliberately misleading the public, but sometimes they answer a particular question that the general public then conflates with a more general truth.

In this case, our experiences align with John Mueller’s statements about domain authority.

I can’t stress enough how important it is not to mistake third-party domain authority scores for the actual signals Google examines to determine a website’s overall quality.

You can use domain authority scores to compare your website to your competitors or even track changes on your website over time. But keep in mind that every domain authority score is a relative measuring stick with no direct bearing on search performance or how Google evaluates sites and pages.

So, how does Google evaluate the quality of websites? Let’s dive into some of the specific signals Google uses to measure domain authority.

How Does Google Evaluate Authority?

Google assesses authority page-by-page rather than considering the authority of an entire website. Google’s ranking systems sort through billions of web pages using hundreds of factors to instantly provide the most valuable and relevant results for searchers.

A series of algorithms make up these ranking systems, each considering various factors (or signals).

Three categories of domain rank signals include:

• Relevance: Analyzing webpage content to assess whether it contains information relevant to the query at hand.
• Links: For external citation authority. Quality backlinks serve as an endorsement of a page.
• User satisfaction/experience: As indicated by some engagement signals and Core Web Vitals. These algorithms analyze signals indicating whether users can view the site as intended on different browsers and devices and whether the page load time is fast enough for users with slow internet connections. 

A Brief Overview of How Domain Ranking Works

First, Google indexes a page to determine its central topic, structure, and user experience. Next, it uses external signals like high-quality backlinks to validate and gauge the page’s level of authority for any given topic.

Why are backlinks an authority indicator?

• Links from third-party sources act as endorsements.
• The more backlinks a website has, the more authoritative and trustworthy it’s considered.
• The authority of referring websites matters, with links from higher quality sources carrying more weight.

Reviews are also important in evaluating authoritativeness. Online reviews can build or break a business’s reputation. They may also help you rank higher in organic search results by sending signals to Google that your site is reputable, trustworthy, and high quality.

Domain Authority FAQs

Why does domain authority matter?

In the broadest sense of the word, authority indicates a level of expertise and quality that matters to Google because it wants to provide the best possible user experience for its users by returning solutions from trusted sources.

Is domain authority a search engine ranking factor?

No, domain authority, which is known by a variety of names, is a proprietary score created and calculated by different SEO tools. There is no guarantee that domain authority scores will correlate with higher rankings.

How do I check my domain authority?

If you think tracking your domain authority is valuable, you can use an SEO tool like Ahrefs or SEMrush to check your domain authority score. Keep in mind that these metrics will differ between tools, so use the same tool to monitor changes over time.

What is a good domain authority score?

Domain authority calculations differ between tools — and the results can vary wildly for the same domain. Because of this, there isn’t a particular number to shoot for. Instead, focus on SEO and backlink parity. If the top-ranking results for your desired keyword have more backlinks than you, focus on your link-building strategy to increase your link velocity and reach competitive parity.

Do sites with a high domain authority rank higher than those with a low DA?

Google strives to surface pages that best meet a searcher’s query — regardless of domain authority. Domain authority is not a Google ranking factor. While you may find that sites with a high DA rank well, that’s likely because they’ve invested in SEO and quality content, not because they have a high domain authority.

What domain authority calculation should you use?

There is no one “best” domain authority calculation. Because domain authority scores are based on trailing metrics, the best bet is to consistently use the same calculation over time if you are interested in tracking them. That way you can compare data week to week or month to month.

Should you use a domain authority checker?

If you want to measure your performance over time, you can track your domain authority score. However, I don’t recommend putting too much stock in it as a KPI. Many SEO tools include a domain authority metric, so you likely won’t need to use an additional tool.

How To Increase Domain Authority with SEO

It takes real effort to improve domain authority in a meaningful way, but partnering with an SEO agency can simplify the process. Victorious can create a custom SEO strategy for your business that includes quality link building services and SEO content writing services to help you improve your domain authority and capture more crucial keywords. No matter what your SEO goals are, our primary focus is your success. Reach out for a free SEO consultation and give yourself an unfair advantage over the competition.