Page Authority is a score (on a 100-point scale) developed by Moz that predicts how well a specific page will rank on search engines. It is based off data from the Mozscape web index and includes link counts, MozRank, MozTrust, and dozens of other factors. It uses a machine learning model to predictively find an algorithm that best correlates with rankings across the thousands of search results that we predict against.
How is Page Authority Scored?
We score Page Authority on a 100-point, logarithmic scale. Thus, it’s easier to grow your score from 20 to 30 than it would be to grow from 70 to 80. We constantly update the algorithm used to calculate Page Authority, so you may see your score fluctuate from time to time.
Page Authority vs. Domain Authority
Whereas Page Authority measures the predictive ranking strength of a single page, Domain Authority measures the strength of entire domains or subdomains. The same is true for metrics such as MozRank and MozTrust.