Domain authority—if SEO were as simple as checking a score, agencies could focus solely on hitting that magic number, right? But while DA is not a ranking factor for Google, and debates persist about the legitimacy of this metric, it remains one of the most popular metrics in SEO. Introduced by Moz, DA provides a way to estimate a website's strength compared to competitors, making it a practical measure for agencies to gauge progress and identify opportunities. For example, tracking changes in a client’s DA score over time can help pinpoint the impact of new backlinks or identify when competitors gain an edge. 

While not perfect, DA gives agencies a way to simplify complex SEO efforts into measurable outcomes that resonate with clients.

In this article, we’ll explore how to select the most effective DA checker for your needs and use it as a tool to enhance client success.

The history of Domain Authority

As previously mentioned, Domain authority (DA) was introduced by Moz as a metric to estimate how likely a website is to rank in search engine results pages (SERPs). It was developed as a response to the complexity of Google's ranking algorithms and was modeled after Google's now-defunct PageRank system, which evaluated the quality and quantity of a page's backlinks. Moz's DA score quickly gained popularity, providing SEOs with a reliable way to benchmark website performance when PageRank was no longer accessible. Over time, DA has evolved, with updates like the 2019 overhaul that enhanced its correlation with SERP rankings using advanced machine learning algorithms.

Despite its widespread adoption, domain authority has been met with skepticism. Critics argue that focusing too heavily on DA can lead to misguided SEO strategies, and Google has explicitly stated that DA is not a ranking factor. Nevertheless, it remains a favored metric due to its simplicity and ability to provide competitive insights. Alternatives like Ahrefs' Website “Authority” Checker and SEMrush's Website Authority Checker have since entered the market, but Moz's DA continues to hold its place as a standard tool in the SEO community.

What is Domain Authority, and why is it important?

In short, a metric developed by Moz to predict how likely a website is to rank on search engine results pages (SERPs). It assigns a score from 1 to 100, with higher scores indicating a stronger likelihood of ranking. DA is calculated using various factors, including the quality and quantity of inbound links, link diversity, and domain trustworthiness. 

But it’s not a ranking factor. Let’s be perfectly clear on that. However, it is widely used in the SEO community to assess a site’s relative strength compared to competitors.

For agencies, domain authority is important because it provides a clear and quantifiable way to track SEO efforts and communicate progress to clients. Monitoring DA helps identify opportunities for improving link-building strategies, addressing gaps in competitive positioning, and showcasing measurable growth. While DA should not be the sole focus of an SEO strategy, it serves as a valuable benchmarking tool, helping agencies create data-driven plans to boost their clients’ online visibility.

Domain Authority vs. Page Authority

While domain authority evaluates the strength of an entire domain, page authority (PA) focuses on the ranking potential of an individual page. Like DA, PA is scored on a scale from 1 to 100 and is calculated using similar factors, such as backlink profiles and page-specific signals.

For agencies, understanding the distinction between DA and PA is critical. DA provides insights into the overall health and strength of a domain, making it useful for long-term strategy and competitive analysis. On the other hand, PA is ideal for evaluating the performance of specific content, such as blog posts or landing pages, and for fine-tuning individual SEO efforts. Leveraging both metrics together allows agencies to craft well-rounded strategies that address both broad and page-specific opportunities.

Common misconceptions

Domain authority (DA) often gets tangled up in SEO myths that refuse to die. Let’s clear the air and tackle the most common ones:

• "Google uses DA for rankings": Nope, Google doesn’t even glance at DA. It's Moz’s baby, not a Google-sanctioned metric.
• "Boost DA, boost rankings": Not quite. DA is relative, so unless it outshines competitors, rankings won't budge.
• "More links = better DA": Only if those links are high-quality. A flood of spammy links won't do you any favors.

How do you calculate Domain Authority, and what’s a good DA score?

Domain authority (DA) is calculated using Moz’s proprietary algorithm, which evaluates multiple factors to estimate the strength of a domain. Some of the key elements include the quality and quantity of inbound links, the diversity of linking domains, and signals related to domain trust. A machine learning model processes these inputs to predict a site’s likelihood of ranking relative to others, producing a score between 1 and 100.

The scoring is logarithmic, meaning it’s easier to grow from a DA of 10 to 20 than from 70 to 80. 

DA is relative, so there’s no universal "good" DA score, but it’s helpful to compare against competitors in each niche. because the "goodness" of a score depends on the industry and competitors. For example, a DA of 30 might be excellent in a niche with low competition, while in highly competitive fields, a score of 50 or higher could be necessary to stand out. 

Ultimately, DA is best used as a comparative and tracking tool rather than an end goal, ensuring your clients’ websites are positioned to outperform their competitors.

Top Domain Authority tools to try