Everything You Need to Know About Google PageRank

Erika Varangouli

Jun 06, 202311 min read
PageRank Guide


Step back in time, and Google PageRank was the SEO metric that everyone talked about.

An increase in your PageRank score was a great demonstrator that your SEO strategy (and, in particular, your link building strategy) was working. 

Fast forward to today, and PageRank is rarely mentioned. 

Not because it’s no longer important. But because it’s no longer a public-facing metric.

In this guide, we’ll dive deep into everything you still need to know about the Google PageRank algorithm.

What Is PageRank?

PageRank is a Google algorithm that measures the importance of webpages based on the quality and quantity of links pointing to them. It considers incoming links as votes, with pages receiving more high-quality links deemed more significant in search results.

Previously, SEOs could see the PageRank score of any webpage via the Google Toolbar.

Google Toolbar
Image Credit: Softpedia

A PageRank score of 0 (PR0) represented the lowest-quality pages. While a page score of 10 (PR10) represented the most authoritative pages.

However, PageRank works on a logarithmic scale. Not a linear scale. 

Many SEOs believe that it has a logarithmic base of five. Meaning each incremental increase represents a fivefold increase in importance.

In this case, a PR4 page would be considered 25 times more important than a PR2 page. 

(Not twice as important, as a linear scale suggests.)

The reason why SEOs became so fixated on this metric is that PageRank passes from one page to another. Meaning that a website can gain authority by being linked to from another that has a higher SEO PageRank score.

Quite simply, PageRank (that is passed between websites by links) helps a website to rank higher. And the algorithm is based around the concept that a page is deemed to be important if other important pages link to it.

History of Google PageRank

Here’s a quick overview of Google PageRank history:

  • April 1, 1998: Larry Page and Sergey Brin publish “The Anatomy of a Large-Scale Hypertextual Web Search Engine”
  • September 1, 1998: Larry Page and Sergey Brin file the first PageRank patent
  • September 4, 1998: Google is incorporated
  • December 11, 2000: Google launches the Google Toolbar
  • June 17, 2004: Google files the reasonable surfer patent
  • October 12, 2006: Google files its “seed sets” patent
  • March 8, 2016: Google announces Google Toolbar’s retirement

Find more details below.

PageRank Is Born

Google’s founders Lawrence Page (Larry Page) and Sergey Brin developed PageRank at Stanford University. 

If you take a look at the paper that introduced Google, you can clearly see PageRank referenced 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 webpage. This ranking is called PageRank … Second, Google utilizes link to improve search results.

“The Anatomy of a Large-Scale Hypertextual Web Search Engine,” Sergey Brin and Larry Page

The paper goes on to explain that “the citation (link) graph of the web is an important resource that has largely gone unused in existing web search engines.”

PageRank is what made Google so unique.

The first PageRank patent was filed in September 1998. And became the original algorithm that Google used to calculate the importance of a webpage. 

In short, Google was formed on the idea that information on the web could be ranked based upon a page’s link popularity. That the more links point to a page, the higher it should rank. 

The Introduction of the Google Toolbar

In 2000, Google launched the Google Toolbar. This was one of the most important stages in PageRank history. Because it enabled users to see the score of any page.

As a result of this, SEOs became fixated on increasing PageRank as a way to improve rankings.

A simple explanation of the approach by many in the early 2000s was that their goal was to get as many links as possible. From webpages with the highest PageRank possible.

This, of course, began to see PageRank manipulated, with money changing hands for links. Links were placed in unnatural locations, and in bulk.

An Updated PageRank Patent

The original PageRank patent from 1998 expired in 2018 and, to the surprise of many, wasn’t renewed. 

Around this time, a former Google employee confirmed that the original algorithm hadn’t been used since 2006.

But that didn’t mean PageRank was dead. Far from it.

The original patent was seemingly replaced by this new one. Which Google filed in 2006.

This patent references “seed sites in the trusted seed sets” and defines these as “... specially selected high-quality pages which provide good web connectivity to other non-seed pages,” with two given examples being the Google Directory (this was still live when the patent was filed) 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 new patent looked to give a ranking score to a webpage based upon how far away it is from a seed set. That said, this patent doesn’t actually reference PageRank (or claim to be an updated version of the algorithm).

Rather, the SEO community has understood that it acts as a PageRank modifier based upon the proximity to the seed set of sites. 

PageRank Patent

Google Retires the PageRank Toolbar

After almost 15 years, Google stopped updating the Google Toolbar. (The last confirmed update was in December 2013.) The company retired it completely in 2016. 

Of course, this didn’t mean Google stopped using PageRank as part of the algorithm. Just that PageRank stopped being a public-facing metric.

Why did Google retire the PageRank toolbar?

SEOs became obsessed with PageRank. And it quickly became the most focused on SEO tactic, even above creating great content and a solid user experience.

The problem: A public PageRank score was easier for SEOs to manipulate.

SEOs knew how they could use PageRank to rank their websites higher. And they took advantage of that.

If we look at this from Google’s perspective, the public-facing PageRank toolbar was the problem. Without this, there was no accurate measure of a webpage’s authority (at least officially). So it was harder to manipulate the score.

Ultimately, SEOs abused PageRank and used it to manipulate page rankings. That was likely a large part of why Google retired the toolbar in 2016.

How PageRank Works

When the patent was first filed and Google’s early algorithm developed, PageRank was based around the theory that a link from one website to another acted as a vote of trust and authority. 

Therefore, the more links (votes) that point to a page, the more it should be trusted. And the higher it should rank.

But, 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.”

A link isn’t simply a straight vote. The authority of a page is taken into account. A link from a PR6 page is ultimately a more authoritative vote than one from a PR2 page.

And this flow of PageRank between pages is sometimes referred to by SEOs as “link juice.”

Let’s look at the calculations behind PageRank:

We assume page A has pages T1...Tn which point to it (i.e., are citations). The parameter d is a damping factor which can be set between 0 and 1. We usually set d to 0.85. There are more details about d in the next section. Also, C(A) is defined as the number of links going out of page A. The PageRank of a page A is given as follows:
PR(A) = (1-d) + d (PR(T1)/C(T1) + ... + PR(Tn)/C(Tn))
Note that the PageRanks form a probability distribution over web pages, so the sum of all web pages’ PageRanks will be one.

“The Anatomy of a Large-Scale Hypertextual Web Search Engine,” Sergey Brin and Larry Page

In simpler terms, the PageRank of Page B is calculated by multiplying the PageRank of Page A by 0.85. This is known as the damping factor.

If Page B then links to Page C, this receives 85% of B’s PageRank. (Which equals 72.25% of Page A’s PageRank).

If a webpage has no links pointing to it, that page doesn’t begin with PR0, but PR0.15.

But things get even more complicated when there is more than one external link on a page. The more links there are on a page, the more their power is diluted.

In other words, it’s more beneficial for SEO when a page links to your site only. Rather than lots of different sites.

Note: The processes described above reference information in a paper published by Google’s founders in 1998. PageRank and related algorithms might have changed since that time.

Factors That Influenced PageRank (and Still Matter)

Of course, there are, and were, factors that influence PageRank. We have already covered the fact that not all links are equal in terms of the SEO PageRank they pass. 

But what are some of the factors that can influence PageRank—or did so in the past?

We will look specifically at:

You need to understand not only what these influencing factors are but also how they apply to SEO today, which you need to be using, and which to avoid.

Anchor Text

Anchor text is the text that a link is attached to.

Google’s original paper stated that “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.”

In the early days of Google, anchor text had a key influence on the rankings of a page.

If you wanted to rank for the term “red shoes,” the more links you had that used that exact term as anchor text, the higher you could rank. (In theory.)

Link building became a race between SEOs to see who could gain as many exact-match anchor text links as possible from high-PageRank pages. 

It worked for some time but was sheer manipulation of Google’s guidelines.

Fast forward to today, and Google considers anchor text manipulation to be a form of link spam. Engaging in this practice can lead to a manual penalty that harms your rankings.

The likelihood of a link being clicked is a key influencer of PageRank. It’s referenced by Google’s reasonable surfer patent (submitted in 2004).

The original PageRank algorithm assigned an equal weight to links on a page. Whereas this patent states that not all links are as likely as one another to be clicked. So links should carry different weights accordingly.

For example, links in the following locations are less likely to be clicked than links in prominent locations. And so should carry less weight.

  • Terms of service pages
  • Banner advertisements
  • Website footers

Internal links are links between pages on your own website. (In contrast to backlinks, which are links to your pages from other domains.)

Internal linking is a powerful SEO tactic.

The idea is that you can help PageRank to flow through your site with a solid internal linking structure.

It’s a particularly good way to drive authority to orphaned pages—pages that aren’t linked from anywhere else. 

You can learn more about how to effectively use this tactic in our guide to internal linking.

Tip: Semrush’s Site Audit tool includes an internal linking report that helps you identify broken links, orphaned pages, poor anchor text, and much more.

Internal Linking report in Site Audit tool

Nofollow links are links that contain the rel=”nofollow” attribute. Originally, nofollow links did not pass PageRank.

Historically, some SEOs used the nofollow attribute to sculpt the flow of PageRank. This practice became known as “PageRank sculpting.”

Those engaging in PageRank sculpting would, for example, write guest posts with links to five different websites. And nofollow all the links except the one that pointed to their website. Ensuring they received all the link juice.

In 2009, Google’s Matt Cutts claimed that PageRank sculpting would not work. Because PageRank would still be diluted by the presence of nofollow links.

In 2019, Google announced that it would treat the nofollow attributes as “hints.” In other words, it would decide whether or not these links should pass PageRank.

For more information, check out our guide to nofollow, sponsored, and UGC links.

Why PageRank Still Matters

Just because there is no longer a toolbar that gives us a webpage’s PageRank score doesn’t mean it’s not still used.

In 2017, Google’s Gary Illyes confirmed on Twitter that the algorithm still uses PageRank.

Screenshot of the Tweet by Gary Illyes

Google’s John Mueller confirmed this again in 2020:

Screenshot of the Tweet by John Mueller

However, the PageRank algorithm is very different than it was originally. As Google’s Matt Cutts wrote in 2009.

“Although we still refer to it as PageRank, Google’s ability to compute reputation based on links has advanced considerably over the years.”

Matt Cutts

PageRank has never gone away. And understanding how it works can only help you to be a better SEO.

Does a Replacement PageRank Metric Exist?

Google does not have official software that allows you to measure PageRank.

However, Semrush’s Authority Score provides an alternative way to gauge your site’s ranking power.

Authority Score is a compound domain score that grades the overall quality of a website. And indicates how impactful a backlink from the site might be for your SEO. 

It’s definitely not a direct stand-in for PageRank. But Authority Score can give you some of the same kind of information that PageRank toolbar scores used to give.

The score (from 0 to 100) is based on:

  • Link Power: Quality and quantity of backlinks
  • Organic Traffic: Estimated monthly average of organic search traffic 
  • Spam Factors: Indicators of a spammy vs. natural link profile

You can check your competitors’ Authority Scores with Semrush’s Backlink Analytics tool.

Just enter a URL then click “Analyze.”

Backlink Analytics tool

You can then add up to four competitors to compare their Authority Scores. And access other helpful metrics.

comparing Authority Scores

Semrush’s Backlink Audit helps you monitor your own Authority Score and backlinks.

Once setup is complete, the “Overview” tab shows your Authority Score trend.

"Overview" section in Backlink Audit tool

Use the “Audit” report to review the backlinks you’ve received.

“Audit” report in Backlink Audit tool

Important note: Authority Score uses backlink data as part of the scoring algorithm but is not intended to directly replace Google PageRank. Instead, it can help you evaluate link opportunities and compare your domain against competitors’.

Bear in mind that third-party metrics are not used in Google’s algorithms. A higher Authority Score does not necessarily translate into higher rankings.

How to Improve Your PageRank

To improve your PageRank, you need to improve your internal links. And build high-quality backlinks to your website.

There are many link building strategies you can use, such as:

  • Outreach: Share your content with publishers who might want to link to it
  • Broken link building: Find broken backlinks and ask owners to fix them
  • Guest blogging: Write high-quality content for relevant sites
  • HARO (Help a Reporter Out): Respond to online media requests

Alternatively, jump straight in with Semrush’s Link Building Tool.

The tool analyzes your competitors’ profiles to find link opportunities. And helps you manage the entire link building process.

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I am responsible for building meaningful connections between Semrush and the SEO community. To achieve this I create content that is helpful, brings new insights and adds value to the community. I am also a public speaker, regular webinar host and awards judge. Mainly fueled by caffeine and music.
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