What Is PA and DA in SEO and How the Two Scores Actually Differ
PA stands for Page Authority. DA stands for Domain Authority. Moz built both metrics. Zero to a hundred is the scale for each one. Ranking potential in search results is what both try to predict. The core difference comes down entirely to scope, plain and simple.
DA measures a whole site’s overall strength. PA measures one specific page’s individual pulling power. Mixing the two up leads to bad conclusions constantly, especially when comparing competitors.
What Page Authority Actually Measures
PA predicts how well one specific URL might rank in search results. That page’s own link profile drives most of it, plus a handful of other page-level signals. Not the whole domain. Just that page.
A single blog post can carry a high PA even sitting on a site with a modest overall DA. Enough quality backlinks pointed directly at that one page raise its individual score independent of the domain around it.
Internal links matter here too. A stronger PA tends to belong to a page linked heavily from other high-authority pages on the same site. An orphaned page buried deep in the site architecture rarely competes.
What Domain Authority Actually Measures
DA looks at the whole domain’s link profile in aggregate. Every page’s backlinks factor into that single number, rolled up into one score representing the site’s overall authority.
Immediate benefit from domain-wide authority is what a new page inherits on an established, high-DA site. Bigger, older sites often out-rank newer competitors for exactly that reason, even with thinner content on a specific page.
Growing DA takes sustained effort across many pages and time. No single page fix moves the whole-domain number much on its own.
Why the Distinction Actually Matters
Individual page optimization is still needed even on a high-DA site with a specific weak page. A poorly built or poorly linked page won’t get saved by domain-wide authority alone.
Reversed circumstances happen too, though. Outranking competitors on a much higher-DA site is possible for a single page. That page’s own PA needs to be strong. Content quality and relevance too. Any single ranking battle comes down to more than site-wide authority alone.
Only part of the story shows up when comparing a site’s DA against a competitor. Comparing the specific page’s PA against the specific competing page usually predicts the actual battle far more accurately.
How PA and DA Interact in Practice
A Calgary SEO strategy benefits from tracking both metrics for different purposes. DA gives a rough read on overall site health and competitive positioning within a niche. PA identifies which specific pages need direct link-building attention.
Building both together compounds results faster than focusing on either alone. Strong individual pages contribute to rising DA over time. A healthy, rising DA in turn lifts new pages faster once they launch.
Neither score should become the actual goal, though. Real authority has useful proxies in both, not the authority itself. Chasing the number directly wastes effort on the wrong target. The genuine backlinks and content quality behind it are what actually matter.
Common Confusion Between PA and DA
A common mistake is assuming a high-DA site guarantees every page on it ranks well. Individual pages still need their own optimization regardless of the domain’s overall strength.
Assuming a low-PA page can never outrank a higher-PA competitor is another one. Content quality still matters alongside the raw authority score. Search intent match and technical factors too.
Treating either metric as something Google itself uses is the most common confusion of all. Neither PA nor DA feeds into Google’s actual ranking algorithm. Both are Moz’s own independent estimates.
Where Moz’s Scoring Model Comes From
Both metrics run on a machine learning model Moz trained against its own backlink index and real-world search results. Neither is an exact science. Both are statistical estimates, calibrated periodically as Moz’s data and models improve.
Moz Link Explorer is the standard tool for checking both scores directly. Any URL entered returns both the domain-level DA and the specific page-level score simultaneously.
Licensed through Moz’s API, third-party tools sometimes display Moz’s own numbers within their dashboards. Confirming the actual source matters, since some competing tools calculate their own separate authority metrics under similar-sounding names.
Frequently Asked Questions
Which matters more, PA or DA?
Depends on the question being asked. DA matters more for overall site health and competitive positioning. PA becomes the more relevant number when predicting whether one specific page will outrank one specific competing page.
Can a page have high PA on a low-DA site?
Yes, absolutely. A high PA score can belong to a single page with strong, relevant backlinks pointed directly at it. Even when the surrounding domain’s overall DA sits much lower.
Do Google rankings depend on PA and DA scores?
Not directly. Google doesn’t use either metric in its own algorithm. Quality backlinks and site authority, the factors both scores estimate, do genuinely affect rankings. That’s why PA and DA often move alongside real ranking performance. See the SEO blog for more on what actually drives Google rankings.
