The Open PageRank initiative was created to bring back Page Rank metrics so that different domains could easily be compared. We do this using Open Source data provided by Common Crawl and Common Search.

The common crawl corpus contains petabytes of data that has been collected over the last 7 years. The July 2017 crawl contains close to 3 billion web pages. While these numbers are not as large the number of pages crawled by any of the top backlink providers, the data is available for anyone for free. We, therefore, decided to use this data to make Page Rank data available to anyone for free forever.