What Is Page Authority? Measuring an Individual Page's Link Strength

Page Authority (PA) is a score from the SEO software company Moz that estimates how well a single URL is likely to rank, based mainly on the links pointing to it. Moz’s Page Authority page describes it as a score that “predicts how well a specific web page will rank on search engine result pages,” calculated “in the same way as Domain Authority but at the individual page level.” It measures one page’s link strength, not the whole site’s, and it is Moz’s estimate, not a Google metric.

How Page Authority Is Calculated

Moz scores PA with a machine learning model that, in its words, identifies “the algorithm that best correlates with rankings across the thousands of SERPs that we predict against.” The inputs are mostly about links. Moz lists, among others, linking URLs, linking root domains, followed and nofollowed links, anchor text distribution, and redirects, and concludes: “As is clearly seen from this partial list, PA is a link-centric metric.” It adds: “PA does not take into consideration specific on-page elements like keyword use or content optimization.”

Two properties shape how to read the number:

• It is logarithmic. Moz uses “a 100-point logarithmic scale,” so “it is significantly easier to grow your score from 20 to 30 than it is to grow from 70 to 80.”
• It moves without the page changing. Moz says it constantly updates the algorithm, “so you may see your score fluctuate from time to time.”

Page Versus Domain

A site’s strength is not spread evenly across its pages. As a hypothetical illustration, not data from any real site: a publisher’s homepage with years of links might score in the 70s, while an article published there last week scores in the 20s, on the same domain. A page-level score captures that gap, which a single domain-wide number cannot.

What Page Authority Is Useful For

• Choosing internal link sources. Pages with high PA hold the most link strength in Moz’s estimate, which makes them candidates to link from when a new page needs support.
• Judging a specific link opportunity. A link from a strong page on a site is a different proposition from a link on the same site’s buried archive page.
• Explaining a ranking gap. Two pages on similar domains can differ widely in the links each has earned.
• Finding weak sections. On large sites, low scores across a category or location section can point to too few internal links.

Page Authority and Ahrefs URL Rating

Ahrefs offers a similar page-level metric. Its URL Rating glossary entry describes UR as representing “the strength of the page’s backlink profile,” measured “on a logarithmic scale from 0 to 100.” The two numbers are not interchangeable. They come from different link indexes and different models, and they count different links. Ahrefs states: “Only ‘dofollow’ links pass UR.” Moz lists nofollowed links among PA’s inputs. A page scoring 35 in both tools has not been measured twice on one scale. Choose one tool and track its metric over time.

Not a Google Ranking Factor

Moz answers the question directly: “No, PA is not an acknowledged Google search engine ranking factor.” Google’s guidance on third-party SEO tools states that third-party tools cannot see Google’s internal ranking data. PA can correlate with rankings because both respond to links, but raising the score is not the goal; earning the links and content quality it partly reflects is.

Limits

• It sees links, not content. Relevance, accuracy, and how well the page answers the search are outside the score.
• New pages start low. A page published yesterday can be excellent and still have a low score because it has had no time to earn links.
• It is relative to Moz’s index. A score can change when Moz’s crawl or model changes.
• It hides the link profile. Two pages with the same score can have very different links; review the referring pages themselves.

Questions About Page Authority

Can a page have higher Page Authority than its site’s Domain Authority?
It can. The two scores come from different inputs, so a single page that earns links from strong sources can score above the domain as a whole, especially on a small or new site.

Should Page Authority appear in client reports?
As supporting data, for example to show which pages are gaining links. Rankings, organic traffic, and conversions describe the outcomes clients pay for; PA belongs beside them, not in their place.