For context, NASA estimates that there are 250 billion stars in the Milky Way galaxy. The scale of the internet is best described as cosmic. For both large enterprises and small businesses, the internet’s vastness presents opportunities and challenges in attracting organic traffic.
If the internet is its own universe, Google is its most prolific voyager. The search engine crawls the web’s expanse 40,000 times per second, evaluating countless websites’ domain authority. Each time, it returns with links to what it believes are the most authoritative content sources for a search query, displaying them on Google’s search engine results pages (SERPs) based on their relevance and domain authority scores.
So, is your site a beacon of authority that will light up searchers’ paths to knowledge or a mote of dust whose content is bound to dwell in the deepest recesses of SERPs?
Understanding your domain authority score can help you answer this question. Are you leveraging SEO tools to improve your site’s visibility or lagging due to a lower domain authority?
There’s no way of knowing for sure. But, domain authority may be the closest way to get an answer. Utilizing a domain authority checker to assess your website’s domain authority can provide valuable insights into how your site might perform in Google rankings.
Table of Contents
Chapter 1: Understanding Domain Authority
Chapter 2: Measuring Domain Authority
Chapter 3: Links and Domain Authority
Chapter 4: Search Engine Optimization and Domain Authority
Chapter 5: Why Domain Authority Changes
Conclusion: Backlink Building Never Stops
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Chapter 1: Understanding Domain Authority
1. What is Domain Authority (DA)?
Domain Authority, often referred to as DA, is a domain authority metric created by Moz that tries to predict how well a website is expected to rank in SERPs, specifically in Google SERPs, with 0 being the lowest probability of ranking well, and 100 being the highest. This domain authority score helps SEO experts gauge the strength of a website in terms of its ability to rank in search engine results. Domain Authority is ranked on a logarithmic scale, meaning it’s harder to increase your score from 60 to 70 than to raise it from 30 to 40. Achieving a high domain authority requires significant effort and a solid SEO strategy, especially as you aim for the upper tiers of the scale.
2. How Does Moz Determine DA?
Moz mainly determines DA by analyzing proprietary metrics available in their SEO tools. These include, but definitely aren’t limited to:
- Linking root domains: The number of unique backlinks to your site, contributing to your link profile.
- Total number of inbound links to your site: Reflecting your site’s overall popularity and reach, especially if they are quality backlinks.
- Spam score: A measure of the level of “spamminess” of sites that link to your site, which can affect your site’s reputation and potentially lead to a lower domain authority.
This comprehensive analysis allows Moz to provide a domain authority score that reflects your site’s potential to rank in search engines.
3. What is DA 2.0?
Domain Authority 2.0, released in 2019, is an updated version of Moz Domain Authority. It analyzes a much larger library of links — 35.5 trillion — enhancing the domain authority metric’s precision. Moz has also switched to a neural model that can better detect link manipulation and spammy links. In essence, more data is being analyzed in a more nuanced way to improve the accuracy of the domain authority scores. This advancement helps SEO experts and small businesses better understand their websites’ domain authority and how it might impact their Google rankings.
4. Is DA a Ranking Factor?
No – it’s a metric made by Moz. Google has nothing to do with DA and DA in no way influences whether or not your site will rank. However, many in the digital marketing community believe that the factors influencing DA closely mirror those that affect Google rankings. So, while DA isn’t a ranking factor, it can be a useful proxy for a site’s potential performance in search engine results.
5. Why Does DA Matter?
Even though it’s not a ranking factor, it’s the closest thing we have to a metric that attempts to predict how well a site will rank. Experts have been known to spar over the accuracy of the metric, which leads to the question — is it an accurate prediction?
The jury is still out on that one, but the consensus is that DA is still valuable for link-building purposes. Search engines favor sites with links from authoritative sources and DA is a fairly reliable metric for determining what qualifies as “an authoritative source” in Google’s eyes. A good domain authority score can help you identify opportunities for off-page SEO improvements and guide your digital marketing efforts.
6. Does DA Accurately Predict How My Site Will Rank?
We haven’t seen definitive proof that it does (see question 5). However, since DA incorporates factors like quality backlinks, spam score and overall link profile, it provides insights into elements that are known to affect search rankings. Using a domain authority checker can help you monitor these factors and adjust your SEO strategy accordingly.
7. How is DA Different from PageRank?
PageRank was Google’s now-defunct version of DA. It ranked a site’s authority on a scale of one to 10 and was shut down in 2016. Unlike PageRank, which was a direct input into Google’s ranking algorithm, Domain Authority is a third-party metric and does not influence Google rankings directly. Understanding the difference can help SEO experts avoid confusion when optimizing search engine results.
8. How is DA Different from Page Authority?
Domain Authority predicts how well domains and subdomains rank, whereas Page Authority is a Moz metric that estimates how well a single page on a particular site will rank. While both are important, focusing on DA helps you understand the overall strength of your website, whereas Page Authority gives insights into specific pages. Balancing both can contribute to a robust SEO strategy.
9. Are There Any Similar Metrics to DA Worth Measuring?
Quite a few. None use the exact same factors to reach a score, but some examples of metrics that attempt to quantify “trustworthiness” and “authority” include the following:
Majestic SEO’s Trust Flow and Citation Flow: Measures the quality and quantity of links, respectively.
SEMrush’s Authority Score: A metric that evaluates the overall quality of a domain and its influence on SEO.
Ahrefs’ Domain Rating: Reflects the strength of a website’s backlink profile on a scale from 0 to 100.
Check Authority Score in SEMrush’s Backlink Analytics tool.
Domain Authority is arguably the most comprehensive regarding the number of links analyzed, but we have yet to encounter hard evidence revealing as much. Evaluating these different domain authority metrics can provide a broader perspective on your website’s performance.
10. Can Sites With Low DA Outrank Sites With High DA?
Absolutely. Microsoft.com, for example, will probably never outrank Brafton for a keyword like “Persona Examples” or “B2B Content Marketing.” A site’s authority, as determined by the quality and quantity of backlinks, is an important factor – whether you call it by DA or any other name. But it’s hardly the only factor. Good domain authority scores can help but on-page SEO, content relevance and technical SEO are also crucial elements in achieving higher rankings.
Chapter 2: Measuring Domain Authority
1. What is a Good DA Score?
Domain Authority is best used as a relative metric that’s gauged against your competitors’ DA scores. For example, a DA score of 60, is good if your competitors average 50. For context, new sites start with a DA score of one. Few major sites such as Facebook, Amazon and YouTube have DA scores at, or near 100. Achieving a good domain authority score should be part of your SEO strategy, especially if you want to outperform competitors in your niche.
2. How Do You Check DA Score?
You can check any site’s DA score for free by installing the MozBar Chrome extension. You can also check DA through one of Moz’s paid tools like Moz Keyword Explorer and Link Explorer. These SEO tools can help you regularly monitor your domain authority score and make informed decisions to improve it.
3. How Often Does Your DA Score Change?
Moz updates your DA score daily. However, it takes a lot to see the needle move. Drastic changes to your DA score may stem from an update from Moz. Most updates from Moz (every three to four weeks) are minor and usually won’t have a pronounced impact on your score. Consistent efforts in link building and content marketing are essential to see a significant increase in your domain authority metric over time.
Chapter 3: Links and Domain Authority
1. What is a Backlink Profile?
A backlink profile — or backlink portfolio — is your total collection of backlinks, also known as inbound links or incoming links. The definition doesn’t implicitly distinguish unique backlinks from the total number of backlinks.
However, most website analytics tools can do that for you. For instance, SEMrush has metrics for “Total Backlinks” for the collective number of inbound links and “Referring Domains” to show the unique sources of those backlinks. Maintaining a healthy link profile with quality backlinks is crucial for improving your domain authority score.
2. Why Is a Backlink Profile So Important to DA?
Because the number of backlinks and where those backlinks come from weigh heavily into Moz’s DA score. Moz cares because Google and Bing care. Search engines look at backlinks as a sort of reputational barometer. Credible sites linking to your domain are votes of confidence. Few or questionable sites linking to your domain could be red flags. A strong backlink profile with quality backlinks from high domain authority websites can significantly boost your domain authority metric.
3. What are ‘Good’ Backlinks?
Any “follow” links to your website that come from a site with a DA score that is higher or comparable to yours. More simply, any backlink to your site from a popular, trustworthy domain is a good link. A “follow” link is any link that does not have the rel=”nofollow” tag. For instance, if an industry magazine links to your site in the body of an article, that would be a follow link. It’s an organic vote of confidence for your site, passing along good “link juice.” Accumulating such backlinks is essential for off-page SEO and improving your domain authority scores.
4. Are ‘Nofollow’ Links Bad News?
Not necessarily. They do not pass along link equity in the way that a follow link might, which means they won’t directly build DA. However, Moz has suggested that nofollow links can have some value when they appear on credible sites. Research conducted by Backlinko also indicates as much.
Using Occam’s Razor, we can also discern that nofollow links have value if generating traffic — for instance, they’re being clicked on in Facebook posts and Yelp comments. Long story short, nofollow links don’t build DA, but can have some SEO value by driving organic traffic.
5. What Are ‘Bad Links’ and How Can They Negatively Impact Your DA?
Links from sites that have low DA or low trust scores — identifiable through Moz and other tools. Moz factors its “Spam Score” — which is based on analysis of 27 features that are known to appear on banned or penalized sites — into link quality, which, in turn, negatively influences DA. Accumulating spammy links can harm your site’s credibility and may even lead to a Google penalty. It’s crucial to monitor your link profile and disavow harmful links to maintain a good domain authority score.
6. How Do “Root Domains” Tie Into Domain Authority?
Root domain refers to the highest level of your site’s structure. For instance, “Yourwebsite.com” might be your root domain. You might have a specific page — “Yourwebsite.com/blog” — within that domain.
A subdomain can also exist as part of your root domain and can have a completely separate DA score from your root domain. An example of a subdomain might be “shopping.yourwebsite.com.” Understanding the difference can help you manage your site’s structure effectively, especially when considering technical SEO aspects that might affect your domain authority scores.
7. How Do Social Media Links Affect DA?
Some sources suggest that social signals do influence DA — though these could be cases of correlation and not causation.
What we do know for certain, is that when links are well-shared on social media, they generate more traffic. This visibility increases the chances that authoritative sources will organically link back to that content. Increased organic traffic and potential for quality backlinks indirectly contribute to a higher domain authority.
8. Does Internal Linking Influence DA?
No. However, it can help pass authority from one page on your site to another. Effective internal linking improves user experience and can enhance your on-page SEO, which might indirectly affect your site’s performance in search engine rankings.
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Chapter 4: Search Engine Optimization and Domain Authority
1. How Does Content Relate to DA?
For starters, you need content because you have to give other sites something to link back to. That content also has to be good enough and well-promoted enough to actually have a chance of earning backlinks. Engaging in content marketing with high-quality, valuable content increases the likelihood of attracting quality backlinks from other high domain authority websites.
Otherwise, Moz has not explicitly stated that it uses high-quality content as a factor in determining DA. But they have implied that great content can ultimately help individual pages rank better on Google, which in turn attracts more backlinks that will directly improve DA. Investing in content that resonates with your audience can boost organic traffic and enhance your domain authority score over time.
2. How Can Search Engine Optimization (SEO) Improve Your DA?
Again, it may seem counter-intuitive, but DA is not meant to score the effectiveness of your SEO strategy.
That said, SEO tactics can be responsible for why certain sites have strong backlink portfolios and others don’t. As mentioned, getting more individual pages on search results and ranking for keywords improves the chances of your content being found via search and that boosts your likelihood of earning quality backlinks. Both on-page and off-page SEO efforts — including technical SEO optimizations — play a role in enhancing your site’s visibility and domain authority.
3. How Does Domain Authority Help/Harm Ranking for Target Keywords?
Sites with higher DA scores have a better chance of ranking for keywords with high difficulty scores. Consider targeting keywords with difficulty scores that are within 10 points of your DA score. This is a type of off-page SEO that can have huge benefits on your site’s overall ranking on search. Conversely, if your domain authority is significantly lower than competitors targeting the same keywords, you might struggle to achieve high rankings.
4. What’s the Relationship Between Guest Blogging and DA?
Blogging on someone else’s website or contributing content to an online magazine are some of the easiest ways to earn high-quality backlinks that improve DA — assuming that site’s DA score is comparable or higher than your own. Engaging in guest blogging allows you to reach new audiences, enhance your link profile and potentially gain higher domain authority.
Chapter 5: Why Domain Authority Changes
1. Why Does Your DA Change?
Finally, we arrive at the titular question — and we saved it for last for a reason. You’ll need a strong understanding of what DA is and how it’s determined to understand how it changes.
And DA can change for multiple reasons:
- Updates to how Moz determines DA: Algorithm changes can affect how your domain authority score is calculated.
- Because DA is a relative metric: Meaning the sites with the highest DA have a score of 100. If one of those sites experiences substantial link growth —as happens from time to time with say, Facebook and Twitter — the entire scale gets skewed and this can influence your DA, particularly if it’s at the lower end.
- Your backlink portfolio changes: Purposeful or incidental and for better or for worse. Gaining quality backlinks can increase your DA, while losing them or acquiring spammy links can decrease it.
2. What Can I Do About It?
Try to figure out the reason behind the change. This isn’t always possible, but there are a few places to look.
First, did Moz upgrade? Look at their “What’s New” page to find out if that’s the reason for the change and try to get to the root of why that upgrade may have positively or negatively affected you.
In the event that you’ve noticed your DA increase — and you’ve ruled out an algorithm change — the first place to go is your backlink portfolio. If it has grown, identify which new referring domains have the best DA, what content they’re linking to and how most users are discovering those pages — social media, direct linking traffic from a few particularly popular web pages, search, etc.
The goal is to figure out what you’re doing right and do more of it. Leveraging SEO tools can help you analyze these trends effectively.
If your DA has gone down — and it’s not an algorithm change — again, look at your backlink profile.
It’s possible it hasn’t experienced any growth. Ideally, your number of backlinks should always be climbing since, on the whole, more links are added to the web each day than removed — meaning, for the most part, the DA scale is always trending upward. Put differently, more backlinks on the web at large suggest that the standard for “authority” is always increasing.
Also try to identify toxic links — those links from sites with malware or adware, from spam sites, link networks that exist solely for link-building purposes, etc. These can be identified using an SEO tool like SEMrush. Alternatively, if you’re using Moz tools, toxic links should reflect in your overall Spam Score.
Either way, you need to identify toxic links and then disavow them through Google Support. Just follow the directions on this page.
Otherwise, look for erroneous page redirects, 404 errors and other broken links on your site that could be hurting your DA. Regularly auditing your site for technical SEO issues can prevent a lower domain authority.
Conclusion: Backlink Building Never Stops
And if it does, that’s a huge neon sign in Google’s eyes that your domain is becoming less relevant to searchers.
Think of your backlink portfolio as a building that should always be getting taller. If it stops growing, it begins to fall behind the other buildings that are still growing. And when this happens, it will almost certainly begin to get pushed down toward the bottom of the biggest, most densely populated digital metropolis of all: SERPs.
Domain Authority estimates how tall your building is relative to the buildings around it, so to speak. And yes, it’s a correlative estimate. But it’s one of the best we have.
Tend to it — in time you’ll be that much more likely to tower over the competition.
Editor’s note: Updated February 2025.
