PageRank: definition, principle and what remains of it in today's SEO

The algorithm that made Google Google — still running but invisible — and what it means for your internal linking and your backlinks

The essentials

  • Definition: PageRank is an algorithm created by Larry Page and Sergey Brin in 1998 that gives every page an authority value proportional to the number and authority of the pages linking to it.
  • Principle: a link is a vote, weighted by the importance of whoever casts it and diluted by the number of links they send out.
  • Today: still used by Google, but no longer shown publicly since 2016; third-party scores (Domain Rating, Trust Flow) are approximations of it.
  • What it means in practice: the quality of your inbound links and the structure of your internal linking are what distribute authority.

The PageRank is the algorithm Google was founded on in 1998. Its idea, borrowed from academic citations: a page is important if important pages cite it. Every link is a vote, and the weight of that vote depends on the authority of the page casting it. The name comes from Larry Page, its co-inventor, as much as from the word "page". Today PageRank is only one signal among hundreds, and Google no longer displays it, but its logic remains at the heart of the "popularity" pillar of SEO.

The principle, without the mathematics

  • Every page holds a quantity of authority (its PageRank).
  • It shares that authority between the pages it links to: the more links it sends out, the less each one passes on.
  • A page receives the sum of what its inbound links pass to it, reduced by a damping factor (historically 0.85) that models a user who stops clicking.
  • The calculation runs iteratively across the whole web until it stabilises.

Two simple consequences: a link from a heavily cited page is worth a great deal, even on its own; a link from a page that sends out hundreds (a directory, a footer) is worth almost nothing.

From public PageRank to third-party scores

PeriodWhat was visible
2000-2013A Google toolbar showing a PageRank from 0 to 10 for each page, updated every few months
2013-2016No more public updates; the toolbar disappears for good in 2016
SincePageRank is still calculated internally (the patent was renewed, and Google has confirmed it), but it is invisible

SEO tools filled the gap with their own scores, calculated on their own link indexes: Domain Rating and URL Rating (Ahrefs), Trust Flow and Citation Flow (Majestic), Domain Authority (Moz), Authority Score (Semrush). These are useful estimates for comparing sites, not Google's PageRank.

What PageRank means today

For inbound links

Quality beats quantity: one backlink from an authoritative page carrying few links passes on more than a hundred directory links. The nofollow and sponsored attributes limit or cancel that transfer. This is the foundation of any serious netlinking strategy.

For internal linking

PageRank also flows inside your site. The home page, which receives the most external links, distributes its authority to the pages it links to; those pages pass it on in turn. Hence three rules: link your strategic pages from the home page and from your strongest pages, limit the number of links per page (a 200-entry menu dilutes everything), and organise content into linked themes, as in a semantic cocoon. Orphan pages, with no internal link, receive nothing.

For redirects

A 301 redirect passes on most of the old URL's PageRank to the new one; a page deleted as a 404 loses it. That is why a redesign without a redirect plan sinks a site (see HTTP status codes).

The limits of the model

PageRank was being gamed from the early 2000s (link farms, purchases, networks), which led Google to add anti-manipulation filters (Penguin), to take the topic of links into account, and to add hundreds of other signals (content, behaviour, freshness, entities). A page's PageRank is no longer enough to rank it; it remains a necessary condition on competitive queries.

Our advice: don't chase an authority score. Ask yourself instead, for each important page, how many quality internal and external links point to it. A service page with no internal link from the home page starts with a handicap the best content in the world won't make up for.

The other popularity concepts (referring domain, anchor, authority) are defined in the SEO glossary.

How GreenRed helps

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Frequently asked questions

Does Google still use PageRank?

Yes. Google has confirmed several times that PageRank remains a ranking signal, calculated internally. What disappeared in 2016 was its public display in the toolbar, not the algorithm itself. It is now combined with hundreds of other signals.

How do I find out my site's PageRank?

You can't any more. The scores offered by SEO tools (Ahrefs' Domain Rating, Majestic's Trust Flow, Moz's Domain Authority) are estimates calculated on their own link indexes; they are useful for comparing sites with one another, but they do not correspond to Google's PageRank.

Does a nofollow link pass PageRank?

In 2019 Google announced it would treat nofollow as a hint rather than an absolute directive, so it may take certain nofollow links into account — with no guarantee. In practice, assume nofollow passes little or no PageRank, but that it brings traffic and diversity to your link profile.

Does internal linking affect PageRank?

Yes, considerably. The authority a site receives (mostly through its home page) is shared out among its pages according to the internal links. Linking a strategic page from the home page and from your strongest pages raises its internal PageRank; an orphan page receives none at all.

From theory to practice

GreenRed measures these metrics on your own site and tells you what to do first.

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