PageRank is the foundational algorithm developed by Google's co-founders Larry Page and Sergey Brin that measures the relative importance of web pages based on the number and quality of links pointing to them. Named after Larry Page, PageRank was the key innovation that made Google's search results dramatically better than competing search engines in the late 1990s. While significantly evolved, PageRank principles continue to underpin how Google assesses page authority today.

How PageRank Works

PageRank operates on a democratic principle: a link from one page to another is treated as a "vote" for the linked page. Pages with more votes (links) receive higher PageRank scores. However, not all votes are equal — a vote from a highly-ranked page is worth more than a vote from a low-ranked page. PageRank is calculated iteratively across the entire web graph: the rank of each page depends on the ranks of the pages linking to it, which in turn depend on their linkers, and so on. The original algorithm distributed PageRank across all outbound links on a page equally — hence the concept of "link juice" being divided among multiple outgoing links.

Key point: Google discontinued the public PageRank toolbar score in 2016. While internal PageRank continues to influence rankings, SEOs now use third-party metrics like Domain Rating (Ahrefs) or Domain Authority (Moz) as proxies for site authority.

PageRank's Evolution

The original PageRank algorithm has been significantly enhanced over the decades:

  • Link quality signals were added — not just quantity but relevance and authority of the linking domain
  • The Penguin algorithm (2012) penalized manipulative link schemes, making earned links essential
  • The nofollow, sponsored, and ugc attributes give webmasters control over which links pass PageRank
  • Topical relevance was integrated — links from contextually relevant pages carry more weight
  • Anchor text analysis was added to understand what a link says about the destination page

Why It Matters for SEO

PageRank is why backlinks remain one of the most important ranking factors in SEO. The fundamental insight — that links represent trust and authority signals from the broader web — has proven enduringly accurate. Building a strong PageRank profile means earning high-quality, relevant backlinks from authoritative websites. Understanding PageRank also informs internal linking strategy: distributing internal link equity strategically from high-authority pages to priority pages improves rankings without any external dependencies.