PageRank

PageRank is the algorithm Google's founders Larry Page and Sergey Brin developed in 1997, and the foundation the entire search engine was built on. It assesses a page's authority from the backlinks pointing at it. A link counts as a recommendation, and recommendations from pages that themselves receive strong links weigh the most.

Google calculates PageRank over repeated passes. Every page sends value onward through its outbound links, the receiving pages pass a share of their own value on again, and the process continues until the picture stabilizes. The formula includes a damping factor that imitates a user who stops clicking at some point. The result is a measure of how likely a random surfer is to end up on one particular page.

Is PageRank still in use?

Yes, though not in the form many remember. Google shut down the public PageRank score in 2016, so the number can no longer be looked up in a toolbar, and internally the principle lives on as one signal among many. Link authority still plays a part in who wins the top rankings, but it weighs less than in the algorithm's early years, and in modern SEO, E-E-A-T takes up far more room.

The principle also reaches beyond Google. When AI assistants pick their sources, they follow related logic: sources that other credible sources refer to get cited more often.