Page Authority (PA)
Page Authority (PA) is a Moz score from 1 to 100 that predicts how well a single page will rank, based on the links pointing to it. It is the page-level version of Domain Authority.
How Page Authority Works
Page Authority is a metric built by Moz, one of the longest-running SEO software companies. It estimates the ranking strength of a single page, scored from 1 to 100. A brand-new page with no links sits near the bottom. A heavily linked page on a major site can score close to the top.
The score comes from Moz’s own link index. Moz crawls the web, records which pages link to which, and feeds that data into a model. The model looks at the number of links pointing to a page, the strength of the pages and sites providing them and other link signals. Moz trains the model using machine learning, comparing link data against real search results so the score predicts ranking ability as closely as possible.
That approach makes PA different from a simple link count. Two pages with the same number of backlinks can have very different scores if one set of links comes from strong, trusted pages and the other from weak ones.
PA uses a logarithmic scale. Moving from 20 to 30 is much easier than moving from 70 to 80, because each step at the top requires far more link strength. That also means small changes near the top represent large real differences.
Because the score is relative to Moz’s index, it can shift when Moz updates its data or model, even if nothing changes on the page itself. Compare PA scores taken at the same time rather than across long gaps.
You can check PA through Moz’s Link Explorer and its browser toolbar, which shows scores directly in search results.
Comparisons with Other Metrics
PA works at the page level. Its sister metric, Domain Authority (DA), works at the site level. Every page on a domain shares the same DA, but each page has its own PA. A homepage might sit at PA 60 while a new blog post on the same site sits at PA 10, even though both share DA 55. That gap is why PA matters whenever a decision concerns a specific page.
Other tools offer similar page-level metrics. Ahrefs has URL Rating (UR), which scores a page’s backlink strength from 0 to 100 using Ahrefs’ own index. Semrush offers Page Authority Score. Majestic’s Trust Flow and Citation Flow can be checked for individual URLs as well as domains.
These metrics measure similar ideas with different data and formulas, so their numbers rarely match. A page might show PA 35, UR 28 and a different score again in Semrush. None of them is wrong. Each reflects its own crawl and model. Comparing several scores often gives a more honest picture than any single one, and a guide to link authority measurement explains how the main metrics differ.
Domain-level scores from other tools, such as Semrush’s Authority Score or Ahrefs’ Domain Rating, play the same role as DA: they judge the site as a whole rather than the page.
None of these metrics are used by Google. They are third-party estimates designed to approximate how search engines might view a page’s links.
Practical Uses
PA is most useful when the decision is about one page.
Evaluating link placements is the most common use. A link passes value from the page that holds it, so the strength of that page matters more than the domain average. When considering a link insertion on an existing article, check the article’s PA. A page with meaningful PA and its own backlinks is usually a better placement than a fresh page with none. A niche edit service that focuses on existing, linked pages relies on this logic.
Analyzing search results is another use. Comparing the PA of pages ranking for a keyword shows how much page-level link strength you may need to compete. If the top results all show high PA, a new page will likely need its own backlinks. If they show low PA, content and relevance may matter more. Many keyword difficulty scores are built partly on this kind of link analysis.
Comparing your own pages helps too. Sorting your site by PA reveals where link strength has built up, often in old popular posts or linkable assets. Those pages make good sources for internal links to pages you want to push higher.
Tracking progress is a final use. Watching the PA of a target page over months shows whether link building is strengthening it, alongside rankings and traffic.
Limitations of Page Authority
PA is an estimate from one company’s data, and it has limits worth keeping in mind.
Google does not use it. A higher PA does not cause higher rankings, and improving PA for its own sake achieves nothing. It can correlate with rankings because both reflect links, but the relationship is indirect.
It depends on Moz’s index. If Moz has not found some of a page’s links, PA will understate its strength. Different tools see different links, which is why scores vary.
It focuses on links. PA does not measure content quality, relevance to a search, user experience or technical health, all of which affect real rankings.
It cannot judge intent or quality fully. A page can carry high PA because of manipulative or irrelevant links that Google ignores. Metrics can be inflated by link schemes in the same way domain scores can.
It moves for reasons unrelated to your page. Model updates and changes elsewhere in the index can shift scores.
Use PA as a relative comparison tool. Compare pages against each other at the same moment, pair the score with traffic, relevance and a manual look at the links behind it, and treat it as one input rather than a target.
Page Authority gives a quick estimate of a single page’s link strength. Use it to judge placements, compare pages and study search results, and pair it with other metrics and real-world signals before making decisions.