Let’s jump in our time machine and go back to the early 2000s when PageRank was the premier SEO metric that everyone talked about. If you’ve been in the SEO game for more than a few years, you likely remember the hype surrounding any updates to the PageRank toolbar. With any luck, your recent efforts would have increased your PageRank score, which meant that Google considered your site more authoritative than before. In short, an increase in your PageRank score meant that your SEO strategy was working.
Fast forward to today when PageRank is rarely mentioned. This is not because it isn’t essential. It’s just that it is no longer a public-facing metric. When SEO professionals can no longer measure something, it tends to fall off everyone’s radar.
This article will cover everything you need to know about PageRank and why it’s still worth discussing today.
What is PageRank?
PageRank is a method for ranking content that Google’s founders Larry Page and Sergey Brin concocted at Stanford University. The most important thing to understand about PageRank is that it’s all about links.
The higher the PageRank of a link, the more authority it possesses. We can simplify the PageRank algorithm to describe it as a means to analyze the importance of a webpage by measuring the quantity and quality of the links that point to it.
The PageRank Score
This should go without saying, but PageRank is a complex algorithm that assigns a score of importance to each piece of content.
As far as the everyday SEO professional was concerned, PageRank was a linear representation of a logarithmic scale ranging from 0 and 10 that was displayed on the PageRank toolbar. A PageRank score of 0 is typically a low-quality website, and only the most authoritative content on the web earns a score of 10. The key to understanding PageRank is that it uses a logarithmic scale. Not sure what that means? No worries, I’ve got you covered!
“A logarithmic scale is a way of displaying numerical data over a very wide range of values in a compact way—typically the largest numbers in the data are hundreds or even thousands of times larger than the smallest numbers.”
— Wikipedia
Search Engine Watch compares PageRanks logarithmic scales to that of the Richter Scale – “It has an estimated base of 4-5. In other words, assuming a base of 5, PR2 links are comparable to 5 PR1 links; a PR6 link is comparable to 5 PR5 links, and so on.” This means that a PR10 link is equal to thousands of PR1 links.
SEO professionals obsessed over this metric because PageRank passes from one page to another. A website can gain authority by earning a link from another with a higher PageRank score.
In the most basic sense, PageRank helps a website rank higher, and the algorithm hinges on the concept that a page is deemed significant if other vital pages link to it.
A Brief History of Google PageRank
The first PageRank patent was filed in 1998, and it became the initial algorithm that Google used to measure the importance of a web page and rank them.
Sergey Brin essentially formed Google based on the idea that we could rank information on the web based solely on a page’s link popularity, such that pages with more inbound links would rank higher than those with fewer links.
Furthermore, the paper that first introduced Google references PageRank when explaining the search engine’s features:
The Google search engine has two important features that help it produce high precision results. First, it makes use of the link structure of the Web to calculate a quality ranking for each web page. This ranking is called PageRank and is described in detail in [Page 98]. Second, Google utilizes link to improve search results.
— The Anatomy of a Large-Scale Hypertextual Web Search Engine, Sergey Brin and Lawrence Page
PageRank is arguably what made Google unique.
The paper later explains how “the citation (link) graph of the web is an important resource that has largely gone unused in existing web search engines.”
The Google Toolbar
Google introduced the toolbar we all remember as how we could see our site’s PageRank score in 2000.
This led to the SEO world’s fixation on increasing PageRank as a metric for improving rankings. It was driven solely by a simplified understanding of the algorithm that eluded the idea that a webpage with the highest number of links should rank the highest.
A basic explanation of the approach many used in the early 2000s was that their ultimate goal was to earn as many links from web pages with as high PageRank as possible.
This naturally led to SEOs manipulating PageRank with people paying for links and the infamous development of link farms.
Fast forward roughly 15 years to when Google stopped updating the public-facing toolbar in 2014 and ultimately retired it in 2016.
Naturally, this doesn’t mean Google stopped using PageRank as part of its algorithm. It just stopped existing as a public-facing metric.
PageRank Patent 2.0
The original PageRank patent expired in 2018 and wasn’t renewed. This makes sense since a former Google employee confirmed that the original algorithm hadn’t been used since 2006.
But that doesn’t mean PageRank was dead.
A new patent replaced the expired one. If you want to explore the differences between the two PageRank patents, you should read Bill Slawski’s analysis.
The new patent references “seed sites in the trusted seed sets.” It defines them as “…specially selected high-quality pages which provide good web connectivity to other non-seed pages,” with examples of The Google Directory and the New York Times.
“(Seed sites) need to be reliable, diverse enough to cover a wide range of fields of public interests & well connected to other sites. They should have large numbers of useful outgoing links to facilitate identifying other useful & high-quality pages, acting as “hubs” on the web.”
The updated patent seemed to assign a ranking score to a web page based on its distance from a seed set. That said, this patent doesn’t directly reference PageRank or claim to be an updated version of the algorithm.
Instead, the SEO community considers it a PageRank modifier based on the proximity to the seed set of sites.
How Does PageRank Work?
PageRank is intriguing and is something every SEO should understand if only to provide context around why links are still one of Google’s top ranking factors.
So how does PageRank work?
When the patent was first filed, and Google developed the early algorithm, it revolved around the theory that a link from one website was a vote of trust and authority. Thus, the more links a page earned, the more trustworthy it was, translating into a higher ranking.
However, as defined in the original paper, “PageRank extends this idea by not counting links from all pages equally, and by normalizing by the number of links on a page.” This means that a link isn’t a pure vote. The authority of the page from which the link originates is considered. A link from a PageRank 6 page is more authoritative than one from a PageRank 2 page.
SEOs commonly refer to this flow of PageRank between pages as “link juice.”
The Equation
Let’s take a look at the actual calculations that fuel PageRank. The original PageRank calculation can be expressed mathematically as follows:
PR(A) = (1-d) + d (PR(T1)/C(T1) + … + PR(Tn)/C(Tn))
Where:
- PR(A) is the PageRank of page A
- d is a damping factor, usually set to 0.85
- T1, T2, …, Tn are the pages that link to page A
- C(T1), C(T2), …, C(Tn) are the number of outbound links on pages T1, T2, …, Tn
- PR(T1), PR(T2), …, PR(Tn) are the PageRank values of pages T1, T2, …, Tn
This formula can be interpreted as follows: the PageRank of a page A is equal to the sum of the PageRank values of all the pages that link to A, divided by the number of outbound links on each of those pages, and weighted by the damping factor d. The damping factor is used to model the behavior of web surfers, who are assumed to click on links with a certain probability randomly.
The formula is applied iteratively, with each iteration updating the PageRank values of all pages based on the PageRank values of the pages that link to them. The process continues until the PageRank values converge to a stable state.
Factors that Influence(d) PageRank and That Still Matter
Naturally, multiple factors influence PageRank. We’ve already reviewed how not all links are equal regarding the amount of PageRank they pass. So what are some of the factors that can influence PageRank? Let’s explore four of these key factors!
Anchor Text
Google’s original paper referred to link anchor text as follows, “the text of links is treated in a special way in our search engine” and that “anchors often provide more accurate descriptions of web pages than the pages themselves.”
Back in the day, anchor text strongly influenced how content ranked.
If you wanted to rank for the term “green shoes,” the more links you earned that used that term as an anchor text, the higher you could rank.
Link building became a race between SEOs to see who could earn as many exact match anchor text links as possible from pages with high PageRank scores.
This worked for some time but was a perfect example of manipulating Google’s Webmaster Guidelines since it qualified as a link scheme.
Fast forward to today, and the overuse of anchor text manipulation will yield toxic links. Google may even hit you with a manual penalty or an algorithmic adjustment.
The Odds of a Link Being Clicked
PageRank also considers the likelihood of a link being clicked, as referenced in Google’s Reasonable Surfer patent.
The original PageRank algorithm assigned equal weight to links on a page. However, the Reasonable Surfer patent states that not all links are as likely as one another to earn a click. Thus, different links have different values, and the value of each link depends on its potential to be clicked.
Examples of links that are less likely to be clicked include “terms of service” links and banner advertisements. Links in a website’s footer or other similar locations are also less likely to be clicked.
Internal Links
Internal linking is a helpful SEO tactic.
A sturdy internal linking structure helps PageRank flow through your website. Once you understand how it works, it’s easy to understand why this tactic is so powerful, especially when linking to pages that lack links from anywhere else.
No Follow Links
NoFollow links were previously used to prevent the flow of PageRank until Google released this statement in 2019.
In the past, SEO professionals used the NoFollow tag to influence the flow of PageRank. For instance, you have five links on a page, and all but one have the NoFollow tag. When NoFollow links were used to stop the flow of PageRank, all of the link juice would have passed through the lone link without the NoFollow tag. However, in 2009, Google’s Matt Cutts confirmed that this would no longer work and that PageRank would now distribute across all links even if a NoFollow tag were present.
Why Did Google Retire the PageRank Toolbar?
SEO professionals obsessed over PageRank, and it quickly became the focal point of every SEO strategy. Yes, even above creating amazing content and a smooth user experience.
The problem was that the PageRank toolbar publicly shared the PageRank score for every page on the web. This made it easier for SEOs to manipulate the algorithm and other factors such as anchor text, NoFollow, and the reasonable surfer model.
The SEO community knew how to use PageRank to rank their websites higher, and they took full advantage of this.
Let’s look at this issue through Google’s eyes – the public-facing PageRank toolbar was the ultimate problem. If the toolbar didn’t exist, there was no longer an accurate or official measure of a web page’s authority.
In the end, SEO professionals abused PageRank and used it to manipulate rankings. This left Google with no choice but to retire the toolbar in 2016.
Why Does PageRank Still Matter Today?
Yes – PageRank is still important today.
Just because the toolbar is retired doesn’t mean that the essence of PageRank is dead and gone.
PageRank hasn’t disappeared, so understanding how it works will help you become a better SEO professional.
Is There a Replacement for the PageRank metric?
Google has yet to release a new version of the PageRank toolbar officially. However, Google still uses the algorithm – we just can’t measure it with a tool today.
Several SEO tools and platforms have developed authority metrics, such as SEMrush’s “Authority Score.” Naturally, this metric uses backlink data as part of its algorithm, but it is not designed to replace PageRank. Again, SEMrush’s “Authority Score” is not intended to replace PageRank.
Third-party metrics are not part of Google’s algorithm. They have never been, and they never will be. However, they are designed to help you measure a site’s relative authority.
Closing Thoughts
PageRank isn’t dead.
The toolbar may no longer exist, but that doesn’t mean we can forget about PageRank and the factors that it takes into consideration.
In many ways, it’s a good thing that the SEO community ended its obsession with this singular metric, given that it contributed towards a shift that means, primarily, the industry isn’t relying on tactics rooted in manipulation.
In the end, SEO professionals abused PageRank, and Google did away with the toolbar because of this. However, many don’t consider this a bad thing!
