Zoom Authority: what it is, what it measures, and how it is calculated
How do you measure the value of a site? What are the parameters to consider? And how long does it take to calculate all the variables? If until a few years ago answering these questions required time and in-depth research, today everything is easier: thanks to SEOZoom‘s Zoom Authority , in fact, we can get a precise and immediate assessment of the authority of each site, measuring exactly the key factors that influence its success in the long run. And all this in an instantaneous way, without loss of time or margin of error: there is no uncertainty typical of traditional metrics, because we don’t just count backlinks or traffic, but real growth opportunities, trust from Google and ranking potential. Let’s find out why our exclusive metric provides a clear, neutral, and accurate snapshot of a site’s true importance in the digital marketplace, but also how and what Zoom Authority measures.
What is Zoom Authority
Zoom Authority is a proprietary metric developed by SEOZoom that measures the authenticity and authority of a website, giving it a score from 0 to 100. This evaluation is based on a series of directly observable signals, making it a particularly reliable tool that is difficult to manipulate.
In short, the ZA is designed to express how much a site is liked by Google, offering an accurate estimate of its position in the competitive digital landscape.
This innovative approach, introduced since the inception of SEOZoom, has allowed the Zoom Authority to quickly become a reference for those involved in SEO and content marketing, as it allows professionals and companies to have a concrete and measurable view of a site’s organic performance , based on actual interactions with search engines. In recent years, ZA has therefore emerged as the most widely used metric for determining the value of sites, including in negotiations in link building campaigns , because it is designed and implemented so that it is reliable and not manipulable, unlike other metrics.
How the ZA is calculated: the parameters taken into account
The strength of Zoom Authority lies in the key parameters on which its evaluation is based. Unlike other metrics that may rely on a variety of signals that are potentially unreliable or subject to manipulation, such as backlinks, ZA focuses on objective data obtained from direct observation of a site’s performance on search engines, and particularly in Google’s SERPs. The four main dimensions that determine the ZA score are:
- Organic traffic: the volume of visitors coming to the site from organic and non-paid searches, an indicator of its visibility and relevance.
- Trust: Google’s trust in the site, i.e., that the site meets sufficient criteria of safety, quality and authority to earn high positions in SERPs.
- Ranking stability: indicates how well the site manages to maintain its positions on Google over months, especially for strategic keywords.
- Growth opportunity: highlights the site’s potential to improve its ranking in the future, based on keywords that could advance to the first page or new trends and emerging content.
By combining these parameters in a weighted manner, Zoom Authority provides a final score that reflects the site’s ability to attract traffic and consolidate into Google’s top positions. This evaluation system makes the ZA a valuable tool for anyone who wants to optimize their digital presence in a strategic and well-informed way, relying on real data and not arbitrary assumptions or estimates.
Why it differs from other metrics
It was also talked about some time ago, reporting the words and doubts of SEO expert Amit Raj on Domain Authority: SEO tools and metrics are certainly useful if used with awareness and shrewdness, but they need to be “interpreted” because they are usually based on predictive values, simplistic if not even manipulable.
And therein lies the big difference with the philosophy behind Zoom Authority, which, like all other SEOZoom metrics, does not only and simplistically consider traffic volume or backlinks. Compared to other well-known SEO metrics, such as Moz’s Domain Authority (DA) or Ahrefs’s Domain Rating (DR), ZA is unbiased: while many competitors focus their evaluations on parameters that are easier to manipulate, such as the number of backlinks acquired by a site, ZA is based solely on signals that reflect Google’s real behavior toward that domain.
This makes it non-targetable to manipulative attempts such as the massive acquisition of low-quality backlinks or the use of questionable practices that temporarily affect ranking. In addition, Zoom Authority updates continuously, thanks to integration with Google’s algorithmic updates , allowing for an up-to-date snapshot of a site’s authority with respect to SERP dynamics. To understand, even if Google changes the algorithm 10 thousand times (and we know that broad core updates are quite frequent!), our feature will automatically adapt.
Metrics such as DA or DR, on the other hand, are based on a variable mix of factors in which the weight assigned to backlinks is often preponderant, leading to ratings that may be poorly reflective of a site’s true quality . Zoom Authority, on the other hand, focuses on the empirical performance of the domain by observing actual Google behavior.
However, it is clear that, just like the other original proprietary metrics (Moz’s DA, Majestic’s Trust Flow, or Ahrefs’ DR), ZA is not something that can really matter to Google, which evaluates sites with its own algorithms, criteria, and ranking factors. Each proprietary tool focuses on the signals it deems most useful and relevant to the data it possesses-for example, Trust Flow is based purely on links, DA is a mix of placements and links, and so on-and it is not possible to determine whether one metric is better or more accurate than another. Rather than reading only the numerical value, in fact, it is more useful to contextualize the data in the context of the tool used and broaden the analysis to include other elements to really evaluate the site.
As far as ZA is concerned, and obviously pulling water to our own mill, compared to other common and widespread metrics it does not take into consideration the number and (alleged) quality of backlinks or other “manipulable” signals, but is based on empirical observation of how Google behaves toward a given site. For this reason, we can call it with sufficient confidence a reliable value , which is based on direct observation of how Google behaves and likes a site, without trying to determine and estimate any other ranking factors or algorithms based on predictive, simplistic, if not manipulable values. To make the parameter more neutral, we reiterate, the ZA is created from the simple observation of the SERPs and Google’s liking toward the site, and moreover it is constantly evolving and adapting with respect to Google’s algorithmic updates.
Why it is essential for those working online
In recent years, the ZA has emerged as the preferred answer in Italy to the questions “How to evaluate a site?”, “What are the parameters to be taken into account to understand if a site is healthy and true?” or “How much is it worth to collaborate with this site in view of link building?”, which are quite frequent for all those who work in online activities, especially if inexperienced or novice.
It may sound like classic self-celebration, but in reality, one only has to see the discussions on the various social channels dedicated to link building negotiations to realize how our ZA has become the most widely used metric for evaluating sites and links, and the reason lies entirely in the philosophy that led us to release such a parameter, which is different from all the others present online.
Zoom Authority now plays a key role for those managing a digital project, whether it is SEO or content marketing; its ability to accurately measure factors related to a site’s organic ranking and stability in SERPs is especially appreciated by those who are committed to building a growth strategy based on hard data.
As mentioned, ZA allows for immediate strategic insight into the site and its future prospects: this makes it irreplaceable for those who need to monitor not only actual organic traffic , but also potential for improvement and growth opportunities that have not yet been fully exploited. Its neutral approach based on real data makes it a long-term tool for those who want to optimize their site and strengthen their digital presence.
Not only that: the ZA has become the priority reference for those involved in link building, precisely because it accurately tracks Google’s liking for a given site. At a glance, it makes it possible to reliably assess the sites from which to acquire links, steering the decision toward domains that not only “appear” authoritative, but also demonstrate stability and effective trust , avoiding false positives due to manipulable metrics such as poor quality backlinks.
ZA and link building: why the most popular metric for evaluating sites
Returning to Domain Authority (which we examine as it is perhaps the most widely known of all), even Moz developer Russ Jones admitted that it represents “a score that predicts the likelihood for a site to rank in SERPs, ” calculated through the combination of a number of internal metrics including measurement of number of links and spam score.
Precisely on the number of backlinks an endless parenthesis can be opened, because it is enough, for example, to take a retrieved site with millions of previous and still active links to distort this value! On the contrary, Zoom Authority manages to analyze what Google thinks of the site: this does not mean that it is perfect or infallible, but that it certainly offers a fairly reliable and useful snapshot of the site’s value, because it takes into account fundamental aspects such as organic traffic, engagement and growth opportunities.
Reading some online conversations in groups and forums specializing in link building, we found various references to our metric: to mention just one, there are those who point out that “the ZA indicates how much a site is liked by Google, the higher the Zoom Authority, the better a website ranks and the better new posts rank, ” summarizing the practical advantages of setting up a reasoned link acquisition strategy also on the study of the host site’s values.
The thing to remember, however, is that SEO does not improvise: all SEO tools, including even ZA, must be used in a reasoned and thoughtful way to reach the goal and have an optimized and well-positioned site.
How Zoom Authority is calculated
To understand how Zoom Authority is calculated we can refer directly to the words of Ivano Di Biasi, CEO and co-founder of SEOZoom, who wrote an explanation trying to use extremely simple language and without going into complex mathematical concepts.
First of all we have to premise that the Zoom Authority is calculated on the whole set of sites indexed and ranked on Google, and more precisely the logarithmic comparison is done on the database of all the domains existing in our database for that specific version of Google: therefore, the metric represents to all intents and purposes a domain ranking within the whole national web landscape, and at the same time it is a parameter that also varies according to the context.
Going into the details of the conception of the ZA, in order to evaluate a website we took into account a number of important signals, provided by the search engines, without trying to invent evaluation algorithms that then would not be matched by the actual performance of the site.
In fact, often, when one tries to evaluate a website with one’s own guesses such as the number or quality of backlinks it receives, one is then confronted with reality-that is, the websites in question do not rank for any important keywords and do not get organic traffic.
For this reason, we have completely excluded backlinks in our Zoom Authority evaluation: only Google knows exactly how to evaluate backlinks, and it would be presumptuous to hazard assumptions and a website from backlinks without any real foundation.
Summarily, the signals and elements we take into account are a weighted mix of number of keywords placed, search volumes of keywords placed, keyword distribution, keyword competition, trends of the last few months (up or down), and, to a small extent, some social aspects; backlinks are not taken into account, as mentioned, since there is no certain way to know how they are really evaluated by Google.
The four signals that make up the Zoom Authority
To be precise, Ivano continues, the signals taken into consideration by Zoom Authority are:
- Traffic from search engines.
- Trust (trust shown by Google for the website in question).
- Stability (how stable the organic ranking of the website is).
- Opportunity (how much the website can grow in the months ahead).
Excluding traffic, which is fairly easy to estimate based on ranking, there is to dwell on the other factors, the calculation of which is done separately with very thorough evaluations.
- Trust of a domain
The question we asked ourselves is, “How much does Google trust the domain in question? How can we measure it?”
To be able to provide an answer, we analyzed the rankings of all the domains in our database and compared them with each other . In this way, we were able to understand how much Google is rewarding a website in rankings, but more importantly, we were able to build an algorithm that can tell us, on a scale of 0 to 100, how much Google is trusting the website in question by placing it in privileged positions or not, compared to other websites.
The trust metric has a strictly analytical basis and sums up the answer to the initial question, namely, “How much does Google trust this site from zero to 100?” in a single value.
- Stability of organic ranking
Evaluating a website only on the basis of its traffic would be very superficial, so we thought of a second important signal, the stability of the site’s ranking.
A website with a stable ranking can rely on many keywords ranked on the first page in high positions. If a few keywords were to lose ranking, the website is not likely to collapse completely, so we can say that it has stable ranking.
If, on the other hand, a website, which has high traffic, has only a handful of top keywords in Google’s top 10, then we can say that it does not enjoy stable ranking, because if one keyword collapses, the website is in danger of losing most of its traffic.
I have deliberately stated the stability evaluation in a simplistic way, but the parameters that lead to the generation of such values are really many and accurate and are part of a quite complex algorithm.
Again, our metrics answer a simple question, “How stable is the site’s ranking from zero to one hundred?”
- Site traffic opportunities
Every website gets traffic, has a more or less stable ranking based on the keywords it has managed to bring into the top 10, but it also has chances to improve its ranking and traffic over time.
We felt it was important to consider this factor as part of Zoom Authority to give a plus to promising websites over those that do not seem to have much chance of improvement.
While to assess stability we looked at positioned keywords, to identify opportunities we analyzed the quantity and quality of keywords not yet on the first page and the likelihood that they might one day reach it.
As with previous cases, the metric answers a question, “How likely is the site to improve ranking on a scale of zero to one hundred?”
How to read Zoom Authority: what the data means
From a technical point of view, as anticipated earlier, the Zoom Authority value ranges from zero to one hundred and takes into account the metrics of the totality of domains in SEOZoom’s database in order to have reference points to arrive at the final calculation. The metrics are based on a logarithmic scale, a design choice that allows sites to be evaluated with increasing accuracy as they move up the rankings.
This approach differs from linear scales, where the differences between grades of measurement are always the same: in the case of the ZA, each increment in value becomes harder to achieve as the score rises, more accurately reflecting theeffort and results needed to progressively improve a site’s performance.
On a practical level, this means that a move from value 20 to 30 in ZA does not carry the same weight as an advancement from 70 to 80: achieving higher scores requires targeted investment and strategies, as the site must demonstrate that it is stable, trustworthy and capable of competing at the highest level in its field. This behavior typical of logarithmic scales makes Zoom Authority a particularly useful indicator for clearly differentiating high-performing sites from those that are only at the beginning of their growth path.
As we analyze the distribution of sites in the Italian market, we can see that most active domains are concentrated in the lower ranges of the ZA scale, generally with scores below 30. In this range, sites are taking their first steps into the world of SEO , and a modest improvement in performance can quickly translate into an increase in score. When, however, a site enters the range between 50 and 60 , the hurdles become more complex and climbing the rankings requires increasingly sophisticated and conscious interventions , such as improving trust , consolidating keyword rankings and strengthening organic traffic.
This logarithmic feature is critically important for those who intend to use Zoom Authority as a guide for developing a solid and realistic digital growth strategy . Going above and beyond a given score is not just a matter of increasing visit volume or acquiring new content: it is necessary to build a solid foundation that demonstrates to Google that the site is capable of competing stably at the highest levels, meeting the search engine’s guidelines and thus earning higher and higher levels of trust.
In other words, significantly improving Zoom Authority requires a focused effort in correcting any structural weaknesses in the site and optimizing every aspect that may affect the score: from continually re-ranking solid keywords, to stabilizing the site’s performance over time. It is a challenge that intensifies as one approaches higher values, and this increasing dynamic is precisely what allows the ZA to be such a reliable and consistent indicator on the many facets of SEO .
Using a logarithmic system helps, in essence, to accurately measure even small but significant differences between an average site and a highly competitive one. When aiming to grow in the upper ranges, every detail makes a difference and requires a sophisticated strategy that knows how to identify room for improvement and areas to consolidate, making the Zoom Authority an indispensable tool for those aiming to make their online project sustainable and high-performing over time.
The complexity of ZA: learning to read the numbers
All of the evaluation factors we have discussed are calculated individually with evaluation algorithms that mirror exactly the evaluation that an experienced SEO would have made: these are not “fancy” algorithms, but concrete numerical evaluations of website returns, scaled to the values of all websites on the web.
In our reasoning, each individual factor, represented by a value from zero to one hundred, cannot have the same specific weight as the others. Therefore, in calculating the Zoom Authority we give a specific weight to each factor, and thus the ZA is by no means the average of all the values of the other factors.
We might therefore find a website with ZA 77 but with a stability factor of 68 (as in the case of the Trenitalia website above). Having an awareness of how this works is essential to be able to make accurate evaluations on any website, and we will shortly see practical examples of values for interpreting specific cases of site evaluations.
Initially, in SEOZoom we were only showing the final Zoom Authority value, but then we decided to also provide individual ratings of the most important factors we take into account. We think this is very useful to have an immediate and complete evaluation of any website, both for personal use and in evaluating websites for backlink acquisition.
In addition, to overcome another objective limitation-namely, the difficulty or even impossibility for sites pertaining to certain sectors, especially niche ones, to reach the level of more generalist, large and authoritative domains-we decided to introduce a second, more sectorial metric , the Topical Zoom Authority, which basically manages to rank each site within a specific topic, effectively creating a new ranking and allowing you to know the best site for each online sector!
How to understand if a site has a good ZA?
Understanding whether a site has good Zoom Authority is not a matter of direct comparison with absolute values, but rather of strategic observation within the context in which the site is operating. As with any metric based on a logarithmic scale, there are no fixed thresholds that define the ZA of a good site; instead, the value must be interpreted according to market competition and the nature of the digital project.
For sites operating in highly competitive industries, a Zoom Authority score above 60 is generally considered an indicator of excellent organic performance, evidence that Google considers that domain authoritative, stable and with ample room for growth. However, there is a crucial difference to consider when analyzing niche domains: here, a lower ZA level may still indicate a strong presence in SERPs related to a specific topic, even though the site may not reach the same heights in terms of score compared to more cross-cutting or mass-market domains.
Usually, a site that falls in the 40-50 range in ZA has begun to consolidate its stability in organic rankings, winning some of Google’s trust and demonstrating consistency in results. This often represents a turning point, as it highlights the presence of effective SEO strategies, which have been able to take the site out of the lower ZA bands, where most domains with poor search engine performance are stationed.
However, when analyzing sites with Zoom Authority below 30, it is easy to see that these are often still early-stage projects , which have not yet established a stable presence in strategic referral queries. This type of domain can have significant growth opportunities, but it is critical that serious work be done on the trust demonstrated to Google, expanding the keyword profile and improving overall performance stability .
The distribution of sites by Zoom Authority score, through tools such as the ZA Observatory, also helps to contextualize what one’s site’s position is in relation to the competition and to understand whether the current score falls within a common range or ranks among the top positions, indicating significant leadership in the field.
Finally, a key factor to consider is not just the numerical value achieved, but the trend of the score over time. A steadily growing ZA site is able to consistently attract organic traffic and consolidate its SEO assets, offering tangible evidence of its development and the soundness of the digital project. Conversely, sharp jolts or sudden fluctuations in the value of ZA may indicate a vulnerability in the strategy adopted, suggesting the need for immediate strategic intervention to avoid broader collapses.
Assessing Zoom Authority: tips and practical examples
To better understand how to assess whether a domain’s ZA is good or not, we can look at the distribution of domains in SEOZoom in the various Zoom Authority bands for Italy, which make it clear to understand how “elite” or fairly common a ZA value can be.
As the table shows, only 5 Italian domains have a ZA greater than 90, while the vast majority of domains have a ZA less than 10.
If our site has a ZA 55, it will surely be a very good result because it is part of the 6791 websites that have a ZA of 51 to 60.
Let’s continue with some practical examples of what ZA values can be and how to interpret them, going on to analyze four different domains.
The first site (www.ilgiornale.it) has a ZA of 74, so it is at the top of the Italian ranking-there are only 21 other sites besides the one analyzed with that level of ZA, and only 128 others exceed this threshold. What we can notice is :
- The site has a trust value of 72, so it is highly rewarded by Google.
- It has a ranking stability of 66, a sign of some below-average fluctuation.
- It has opportunities of 72, so still potential for growth.
Thanks to SEOZoom we can say-with a sufficient degree of certainty-that this site is highly rewarded by Google, has sufficiently stable rankings, and lots of opportunities for further growth in the future.
The case of the second site (tonightintv) is different: although it has the same ZA as the previous one, and thus 74, the ZO and ZS values are lower (60 and 58, respectively), thus indicating some turbulence in the relationship with Google and more uncertain traffic, also in the future.
Let’s go on with another site (previsioni.meteogiornale.it) that gives us a very interesting angle of analysis. Here the overall ZA is 48, an average or slightly below average level, and certainly the level of stability is “worrying,” because the ZS is 35: in short, at a glance we could say that the site is doing traffic and is quite rewarded by Google, but with a limited number of well-positioned keywords, which therefore could lead to a serious drop in traffic in case of a negative change. At the same time, however, we note that the site is in the running for ranking for a good number of keywords because it has 58 of opportunity, so it has good room for improvement. Ultimately, it is a site to be monitored because it currently has a rather unstable ranking, is getting traffic from a limited number of keywords and could lose it abruptly, but at the same time it could-with the appropriate improvement measures-solidify its trust and grow.
This scenario is even more evident in the last example (buontutto): the analyzed site has ZA of 64, but breaking down its factors we notice that the level of stability is rather low (47), as is that of opportunity (46). It is a risky site, even for the specific niche of activity, which cannot be relied on too much in terms of collaboration and evaluation, because it seems exposed to potential downgrading.
Deepening site analysis with TZA and the ZA Observatory
But SEOZoom also allows a site’s evaluation analysis to be taken to an even deeper level. Indeed, when it comes to authenticity and authority in the competitive environment of a specific industry, a global comparison does not always provide a clear and complete picture, and especially in niche industries it may be difficult to compete or compare performance with generalist giants.
This is where Topical Zoom Authority comes in, which we have said is SEOZoom ‘s metric designed to offer a more precise sectoral picture , designed to perform the measurement of a site’s authority contextualized within its own sector. This approach becomes particularly relevant for those projects that operate precisely in niche markets or vertical areas, where it may be difficult to compete directly with large brands and generalist sites, because it allows a domain to be evaluated not only in relation to the global market, but in the precise area in which it operates, facilitating rapid understanding of the competitiveness of even small or medium-sized projects.
With Topical Zoom Authority it is possible to obtain a more accurate sectoral assessment: it is not just about competing for global positions, but about understanding the actual value of the examined site compared to that of its direct competitors. This means that Topical ZA allows us to identify market leaders within specific niches and to understand what level of authority is achieved compared to other domains competing on the same topics or targets.
Completing the picture is the ZA Observatory, a tool that provides a detailed overview of the distribution of Zoom Authority among the domains in our database. The tables and graphs in the Observatory allow us to understand which score range the site is in and how many domains are in the various classes of ZA in the Italian market (and of the other databases in SZ). This feature becomes particularly useful both to evaluate the site in terms of link building, and to better understand the competitive environment in which we are moving.
TheZA Observatory also helps us track periodic fluctuations in scores through two very useful tools: the Winner Domains and the Loser Domains. The former lists include domains that gained points in ZA compared to the previous monitoring, while the latter show domains that lost ZA when comparing with the previous survey cycle. This information can offer valuable insights, for example in the periods following Google algorithm updates , to find out which sites have benefited from the updates and which have suffered declines in visibility or penalties.
