About 10 years ago, the PageRank algorithm was introduced as one of the SEO metrics, and accordingly, Google also introduced a toolbar called the PageRank Toolbar, which all users could use. The way this tool worked was that the higher your PageRank score, the more credible your site was considered by Google. This score was ranked from 0 to 10, and the stronger your link-building strategy and the more links you received, the higher your credibility.
Let’s quickly jump to 2021, a time when this algorithm is rarely discussed. However, the reason for this is not the insignificance of the algorithm! It’s just no longer considered a public metric, and only some Google employees have access to this data. In this article, we will deeply explore everything you need to know about Google’s PageRank algorithm and its importance in 2021.
What is the PageRank algorithm?
PageRank is a system for ranking web pages created by Google’s founders, Larry Page and Sergey Brin, at Stanford University. What we need to pay attention to is that the basis of this Google algorithm is about links and focuses on them. In fact, the higher a link’s PageRank score, the more credible that link will be.
How is the PageRank Algorithm score calculated?
This algorithm was a linear representation of a logarithmic scale between 0 and 10, with the final number displayed in the PageRank toolbar. A score of 0 in PageRank indicates low quality of a site, while a score of 10 identifies the most credible web pages.
To better understand how this algorithm scores, Wikipedia explains: “A logarithmic scale is a way of displaying numerical data over a wide range of values in a compact form. Typically, the largest numbers in the data are hundreds or even thousands of times larger than the smallest numbers.”
As reported in Search Engine Watch: “This is an estimated base of 5-4. In other words, assuming a base of 5, PR2 links are comparable to 5 PR1 links; PR6 links are comparable to 5 PR5 links, and so on.”
It is easy to see that under such conditions, a PR10 link is comparable to thousands of PR1 links.
The reason is that PageRank transfers from one page to another. This means that a website can gain credibility by linking to another page with a higher score. Simply put, PageRank (which transfers through links between websites) helps rank websites and is based on the concept that if pages linked to it are important, that page is also considered important.
Google currently uses this feature as part of its algorithm, although what we see now is quite different from the original and much more complex.
Introduction of the Google Toolbar
In 2000, Google introduced a toolbar that we all now remember as the way to view the PageRank score of our (and our competitors’) sites. (This toolbar is no longer available, and we only had the chance to use this feature in those years.)
As a result of this toolbar, SEO specialists focused on increasing the credibility of pages through link-building as a measure to improve site rankings. In fact, most of them had a simplistic understanding of the algorithm that suggested a web page with the most links should have the highest rank.
This approach caused the functionality of PageRank to change! How? By paying money for links from reputable sites or the emergence of sites called link farms.
After 15 years, Google stopped updating this toolbar in 2014 (with the last confirmed update in December 2013) and completely discontinued it in 2016. However, this does not mean that Google has stopped using PageRank as part of its algorithm. It just no longer considers this factor a public and 100% reliable metric for ranking.
How Does PageRank Algorithm Work?
This is a topic that every SEO specialist must deeply understand. The content produced is the reason those links rank higher on Google. But how?
When Google’s initial algorithm was developed, it was based on the theory that creating a link from one website to another would act as a factor in increasing the site’s credibility. Therefore, the more links (votes) a page has, the more trust it gains, and thus, the higher its rank.
However, as defined in the original Google article, “PageRank extends this idea by equally counting links from all pages and normalizing by the number of links on a page.”
A link is not a direct vote by itself. The authority of a page must also be considered. A link from a page with a PageRank of six is ultimately more credible than a link from a page with a PageRank of two. Sometimes, SEO specialists refer to this flow of link authority between pages as “link juice.”
But let’s see what calculations are behind the scenes: “We assume page A has pages T1 … Tn linking to it. The parameter d is a damping factor that can be set between zero and one. We usually set d to 0.85. More details about d are in the next section. Also, C(A) is defined as the number of links going out from page A. The PageRank of page A is given as:
Note that this algorithm forms a probability distribution over web pages, so the sum of PageRanks of all web pages will be one.”
In simpler terms, it means that the authority of page B is calculated by multiplying the PageRank of page A by 0.85, known as the damping factor. If page B links to page C, it receives 85% of the authority of page B (and 72.25% from page A).
If a web page has no links, it doesn’t start with a zero authority; instead, the intended value for it is 0.15. However, when there are more than one external link on the page, things can get even more complex.
As Barry Schwartz stated in a 2004 post on Search Engine Roundtable: “If you place a link from page A to page B, page A will distribute its authority to page B. The PageRank of page A will not decline or lose value by linking. But, when there are more links on page A, these links are considered less valuable by this algorithm.”
It might seem a bit confusing, which is normal because the way this algorithm works is complex. Understanding its detailed workings requires further investigation and study.
Which Factors Influence PageRank Algorithm and Still Matter?
There have always been factors that influence PageRank. We have previously explained that not all links are equal. However, only certain factors can affect a page’s credibility. What are these factors? Specifically, we will examine the following:
- Anchor Text
- Likelihood of Clicks
- Internal Links in Text
- Nofollow Links
Not only is it essential to recognize these influential factors, but you also need to understand how to apply them in SEO in 2021 and when to use them.
Anchor Text
The original Google article mentions that “in our search engine, we treat link text in a special way” and refers to the anchor text in links, saying, “Anchor texts often provide a more accurate description of the web pages’ nature.”
In earlier years, anchor text had a fundamental impact on a page’s ranking. If you wanted to rank for the term “red shoes,” the more links you had using this term as anchor text, the higher your rank on Google.
Link-building turned into a competition among SEO specialists, with everyone trying to rise to the top of Google search results for their targeted keywords by using anchor texts. This approach worked (for a while) and was effective, but it was merely a way to manipulate Google’s Webmaster Guidelines and was specifically considered a link scheme.
When we reach 2021, we see that overusing manipulated anchor texts leads to spammy, low-quality links and possibly penalties from Google.
Likelihood of Clicking on a Link
The likelihood of clicking on a link is one of the most influential factors on page credibility from Google’s perspective, as highlighted in Google’s reasonable surfer patent. The original PageRank algorithm assigned equal weight to all links on a page. However, the 2004 Reasonable Surfer patent shows that not all links are likely to be clicked on. Therefore, each link is given different amounts of weight based on its potential clickability.
Examples of links with low clickability are “Terms of Service” links and banner ads. Links in the footer of a page also tend to get fewer clicks.
Internal Links
Internal linking is a powerful SEO tactic, and there’s a good reason to use it. You can help your pages gain credibility by having a well-structured internal linking system that allows link equity to flow throughout your site. Once you understand how it works, it’s easy to see why this tactic can significantly impact your pages’ credibility, especially when linking to pages that haven’t received links from elsewhere.
NoFollow Links
NoFollow links always prevented the flow of PageRank, until recently when this changed. Historically, SEO specialists sometimes used the NoFollow attribute to create PageRank pathways. If a page had five external links and four of these links had NoFollow tags, the PageRank would only pass through the link with the Follow tag. In 2009, Matt Cutts from Google confirmed that this method no longer worked and that even if a link has the NoFollow attribute, PageRank is distributed through all links.
Why Did Google Discontinue the Toolbar?
This Google toolbar made content specialists more sensitive to it, driving all their efforts toward obtaining higher scores. This sensitivity reached the point where these specialists no longer gave much importance to producing good content or improving user experience. The problem was that publicly sharing page authority scores allowed SEO specialists to engage in an endless competition, manipulating anchor text, NoFollow links, and more to boost their PageRank above their competitors. SEO specialists knew how to leverage this feature to get higher rankings for their websites and used this advantage.
From Google’s perspective, the public nature of the PageRank toolbar was the main issue. Without it, there was no accurate (at least officially) measure of a web page’s authority. Ultimately, SEO specialists abused it to manipulate their site rankings, leaving Google no choice but to discontinue the toolbar in 2016 and introduce the Penguin algorithm to combat unnatural link-building and spam.
Why Does PageRank Algorithm Still Matter in 2024?
Just because there is no longer a toolbar to show us a web page’s score doesn’t mean it is obsolete. In 2017, Gary Illyes from Google confirmed on Twitter that they still use this algorithm. Remember that PageRank has never disappeared, and understanding how it works will help you become a better SEO specialist.
Is There a Metric to Replace PageRank?
Google has never officially released a new version of this toolbar, but they still use this algorithm extensively. Several SEO software tools and platforms have their own authority metrics, and MOZ is one of them.
Authority Score
Authority Score is a composite domain score that rates the overall quality of a website and indicates how much getting a backlink from a site can impact your SEO. Authority Score is calculated based on:
- Backlink data, including referring domains, follow links, NoFollow links, and more
- Organic search data, including organic search traffic and keyword positions
- Website traffic data (monthly visits)
This metric uses backlink data as part of the scoring algorithm but is not intended to be a direct replacement for PageRank. It’s important to note that third-party metrics are not used in Google’s algorithm and have never been part of it. However, they still exist to help you measure your site’s relative authority compared to competitors’ websites.
Remember, PageRank is still active and functioning. We may no longer see the toolbar, but this doesn’t mean we don’t need to understand how it works and the factors influencing it.
