Page Authority: The Complete Guide to Understanding, Checking, and Improving Your Score

Everything you need to know about Moz’s Page Authority metric — how it’s calculated, what it means for your rankings, and exactly how to use it to outperform competitors in search.

• ▸Page Authority is a Moz metric — scored 1–100 on a logarithmic scale — that predicts how likely a single URL is to rank highly in Google search results.
• ▸Its primary inputs are the quantity and quality of external backlinks — especially the number of unique linking root domains — pointing to that specific page.
• ▸PA is a relative metric — it shifts as Moz’s index grows and as the ML model is periodically retrained against fresh Google SERP data.
• ▸PA correlates with Google rankings but is not a Google ranking factor — it is a third-party proxy metric with no direct connection to Google’s algorithm.
• ▸Domain Authority (DA) scores an entire domain; Page Authority scores a single URL. Both use the same 1–100 logarithmic scale.
• ▸PA is best used as a competitive benchmarking tool — compare it against the actual pages currently ranking for your target keyword, not an abstract number.
• ▸PA does not measure content quality, keyword relevance, or technical SEO — it measures link equity only. It must be used alongside other signals for accurate analysis.

What Is Page Authority? A Complete Definition

Page Authority is a search engine ranking prediction score developed by Moz that estimates how likely a single webpage — a specific URL — is to rank highly in search engine results pages (SERPs). It was designed to give SEO practitioners a standardized, page-level signal for benchmarking link equity, evaluating competitors, and making data-driven decisions about link-building investment.

Unlike a raw backlink count, PA distills dozens of link-based signals into a single predictive number using a machine-learning algorithm trained directly against real Google search results. This means the score reflects not just how many links a page has accumulated, but how closely that link profile mirrors what Google actually rewards in its rankings — making it a far more nuanced measure than any single link metric could provide.

PA scores range from 1 to 100 on a logarithmic scale. Brand-new pages without any inbound links begin at 1. The most authoritative pages on the web — major Wikipedia articles, BBC news pages, prominent government resources — tend to cluster between 70 and 100. Pages that rank competitively for moderately difficult keywords most often fall in the 40–65 range. Most established pages on credible sites sit somewhere between 20 and 45.

How Page Authority Differs From Google’s PageRank

Moz’s Page Authority is frequently confused with Google’s internal PageRank algorithm. They share a conceptual lineage — both evaluate link-based authority — but they are entirely separate systems. PageRank is Google’s private, proprietary signal that directly influences real search rankings. Page Authority is a public, third-party metric from Moz designed to predict what Google’s systems might favor — it has no direct connection to Google’s algorithm and plays no role in how Google ranks pages.

Because PA is modeled against actual SERP outcome data, it tends to correlate meaningfully with rankings. But correlation is not causation. A high PA score is a strong indicator that a page has accumulated the kind of link equity that tends to perform well — not a guarantee of any particular ranking position.

A Brief History of Page Authority

Moz introduced Domain Authority and Page Authority as part of its broader effort to give SEOs a standardized alternative to Google’s publicly visible (and then later deprecated) Toolbar PageRank. When Google stopped updating its public PageRank scores in 2016 and eventually removed Toolbar PageRank entirely, Moz’s PA became one of the most widely adopted substitutes for understanding page-level link equity. Today PA is integrated into Moz’s full suite of tools including Link Explorer, MozBar, Moz Pro Campaigns, and the Moz API.

Moz has periodically updated its underlying ML model to keep the metric as predictive as possible — most notably with the Page Authority 2.0 update, which incorporated additional spam-detection signals and recalibrated the scoring distribution. Each major model update resets scores across the entire index, which has important implications for how SEOs should interpret sudden PA changes.

How Moz Calculates Page Authority: The Core Formula Explained

Moz does not publish a literal mathematical formula for Page Authority. Instead, it trains a machine-learning algorithm against real Google search result data to produce a single output score that best predicts actual Google ranking performance. The model ingests a wide array of link-based metrics collected from Moz’s own crawl index — Link Explorer — and uses those features to generate a score that most accurately forecasts page-level ranking ability.

The most heavily weighted inputs to the model include:

• Linking Root Domains
  The number of unique domains with at least one link pointing to the target page. This is arguably the single most powerful signal in the entire model. A hundred links from one domain count far less than one link each from a hundred different authoritative domains. Diversity of linking sources is paramount.
• Total External Links
  The raw count of all inbound links pointing to the page. While volume contributes to the score, uniqueness — the number of distinct linking root domains — is weighted more heavily than sheer link quantity from any single source.
• MozRank
  Moz’s own link popularity score, modeled on a flow-of-authority concept similar in spirit to Google’s PageRank. MozRank reflects both the quantity and quality of inbound links and flows through the link graph from page to page, meaning the authority of your linking sources directly influences your MozRank.
• MozTrust
  A trust-oriented signal measuring how closely a page is connected to trusted “seed” sites — predominantly government (.gov) and educational (.edu) domains. Pages that earn links from inherently authoritative, trusted sources receive elevated MozTrust, which boosts their overall PA score disproportionately relative to other link types.
• Link Profile Quality (Linking Page PA)
  The PA scores of the pages that link to your target page. A single editorial link from a PA 85 page transfers dramatically more authority than 100 links from PA 10 pages. The quality of your linking sources matters as much as — and often more than — the number of them.
• Link Anchor Text Distribution
  The diversity and relevance of anchor text across inbound links contributes a secondary signal to the model. A natural, varied anchor text profile is preferred; over-optimization with exact-match anchor text can suppress PA relative to what the raw link count might suggest.

The Logarithmic Scale: Why Improving Page Authority Gets Exponentially Harder

The 1–100 range is logarithmic, not linear. This is one of the most consequential details about how Page Authority works, and a frequent source of confusion and frustration for SEOs at every level.

On a linear scale, moving from PA 10 to PA 20 would require the same incremental effort as moving from PA 60 to PA 70. On a logarithmic scale, the link equity required to advance grows exponentially as you climb. Moving a page from PA 60 to PA 70 can require more authoritative backlinks than building an entirely new page from PA 0 all the way to PA 40. The compression at the top is extreme.

What Different PA Ranges Mean in Practice

“

Page Authority is best used as a comparative tool — not an absolute grade. Two points of PA difference at the top of the scale can represent millions of links of difference in the underlying data.

— Moz, Page Authority Documentation

Because of this logarithmic compression, absolute PA numbers matter far less than relative comparisons within your specific competitive SERP. A page with PA 45 competing against pages with PA 38–42 is well-positioned. That same PA 45 page competing against PA 65+ pages faces an enormous structural disadvantage that content quality alone cannot overcome without significant link-building investment.

Page Authority vs. Domain Authority: Key Differences and When to Use Each

Moz produces two closely related authority metrics used together in SEO workflows, but measuring fundamentally different things. Many SEOs conflate them or use them interchangeably — a mistake that leads to flawed competitive analysis.

When to Use Page Authority vs. Domain Authority

Use Page Authority when you are doing page-level competitive analysis — for example, comparing the specific URLs currently ranking for a target keyword. If the top 10 results for your keyword all have PA scores between 45 and 60, that benchmark tells you what link equity you need at the individual page level to compete. PA is the right metric when you are analyzing pages that rank, not sites in general.

Use Domain Authority when you are prospecting for link-building targets, evaluating whether an outreach candidate site is worth pursuing, or assessing the overall authority of a competing website’s footprint. A high-DA site is generally a strong link source regardless of which specific page links to you.

Page Authority vs. Other SEO Tool Metrics: Moz, Ahrefs, Semrush & Majestic Compared

“Page Authority” is a Moz-specific term, but every major SEO platform has an equivalent page-level authority metric. Understanding how they differ prevents costly analytical errors — especially when you are working across multiple tools or comparing scores from different platforms.

These metrics are not interchangeable. Each tool operates on a different crawl index with different size, recency, and coverage characteristics. A page with Moz PA 45 and Ahrefs UR 58 is not contradictory — it simply reflects that each tool has crawled a different slice of the web and applied a different model. Do not compare PA scores from Moz with UR scores from Ahrefs as if they were equivalent.

The best practice is to pick one tool for your primary authority benchmarking and use it consistently. Mixing tools in the same competitive analysis dataset will produce misleading conclusions. If you use Moz’s PA for evaluating your page-level competitive landscape today, use it again when measuring progress six months later.

Why Page Authority Scores Fluctuate (Even Without Changes to Your Page)

One of the most common SEO frustrations is watching a Page Authority score drop despite no lost links and no changes to the page. This happens for two distinct structural reasons that have nothing to do with anything you did or didn’t do:

How Often Does Moz Update Page Authority Scores?

Moz updates PA scores approximately every 3 to 4 weeks as its web crawler re-indexes links and the underlying link data refreshes. There is always a lag between when a new backlink is acquired and when it appears in your PA score. Major model retraining events occur less frequently — typically a few times per year — but produce more dramatic, index-wide score shifts. Plan your PA monitoring cadence accordingly: spot-check monthly, analyze trends quarterly.

How to Check Page Authority for Any URL: 4 Free and Paid Methods

Moz provides multiple ways to look up Page Authority, from free browser tools to enterprise-scale API access. Here are all available methods and when to use each:

1. 1
   Moz Link Explorer (Free & Pro)

   Enter any URL at moz.com/link-explorer to see its PA score alongside linking domains, total inbound links, and spam score. Free Moz accounts receive a limited number of daily queries. Moz Pro subscribers get unlimited access, historical PA trend data, and bulk URL analysis capabilities.

2. 2
   MozBar Browser Extension (Free)

   The MozBar is a free Chrome extension that overlays PA and DA scores directly on any webpage as you browse. Critically, it also shows PA for every single result simultaneously on a Google SERP page — making it the fastest possible tool for quick competitive research without leaving your browser or manually entering each URL.

3. 3
   Moz Pro Campaigns

   Within a Moz Pro campaign, you can track PA for your own pages over time, monitor specific competitor page PA scores, and receive alerts when significant changes occur. This is the most systematic approach to long-term PA tracking rather than one-off spot checks — essential for monitoring whether your link-building efforts are producing measurable PA movement over months.

4. 4
   Moz API (Bulk & Enterprise Access)

   For enterprise-scale workflows, Moz’s API allows programmatic retrieval of PA scores for thousands of URLs at once. You can integrate PA data into custom reporting dashboards, automated competitive monitoring systems, or content audit pipelines — making it practical to track page-level authority across tens of thousands of URLs that would be impractical to check manually.

How to Improve Your Page Authority Score: 7 Proven Strategies

Because Page Authority is driven almost entirely by link-based signals, all practical strategies for improving it focus on acquiring high-quality links and optimizing how link equity is distributed across your site. Here are the most effective approaches, ordered by typical impact:

How to Use Page Authority in Your SEO Strategy: 5 Practical Applications

PA becomes genuinely powerful when deployed systematically as a competitive analysis and prioritization framework. These are the five highest-value strategic applications:

1. SERP Difficulty Assessment Before Creating Content

Before investing significant resources into targeting a keyword, pull PA scores for the top 10 ranking pages using MozBar or Link Explorer. If the average PA of first-page results is 55–65 and your target page has PA 30, you face a significant link equity gap. This doesn’t make the keyword unattainable — content quality, on-page optimization, and search intent alignment still matter substantially — but it reveals the scale of link-building investment required to compete at the page level. Factor PA gaps into your keyword selection and content roadmap decisions.

2. Link Prospecting and Outreach Prioritization

When identifying pages for backlink outreach or unlinked brand mention conversion, PA tells you precisely how much authority each potential link would actually transfer. Prioritize outreach to pages with PA 50+ within your niche. Even a handful of high-PA links will do more for your target page’s ranking ability than dozens of links from PA 15–20 sources. Filter your outreach prospect lists by PA as a primary triage criterion.

3. Content Audit and Internal Linking Hub Identification

Map the PA scores of all your existing pages to identify which carry the strongest link equity. These high-PA pages are your most valuable internal linking hubs. Adding contextual links from them to newer, lower-PA target pages is one of the fastest and most cost-effective ways to lift page-level authority without acquiring any new external links. This internal link audit should be a recurring quarterly activity, not a one-time exercise.

4. Competitor Gap Analysis and Priority Targeting

Compare your PA against competitors for every keyword you are actively targeting. Pages where you are closest to parity represent your highest-probability ranking opportunities with the most modest incremental investment. A competitor with PA 55 versus your PA 48 is a far more actionable target than one with PA 55 versus your PA 22. Focus your link-building budget on closing small gaps first for the quickest measurable ranking gains.

5. Measuring Link-Building Campaign Effectiveness

Track PA for your target pages at consistent intervals — monthly is a reasonable cadence — alongside competitor pages for the same keywords. Relative PA movement over time is a leading indicator that your link-building is working before ranking changes become visible. If competitors’ PA scores are rising faster than yours, it signals a structural link velocity problem requiring strategy adjustment. PA trend data gives you a feedback signal weeks or months before Google ranking changes surface.

Page Authority Benchmarks by Industry and Niche

Because PA is a relative metric, “what is a good Page Authority score” has no universal answer — it depends entirely on which SERPs you are competing in. These are representative PA ranges for first-page results across common niche categories, based on typical competitive landscapes:

These ranges are approximations based on typical competitive landscapes and will vary considerably based on keyword specificity, geographic targeting, and the specific sub-niche. Always run the actual competing SERPs through Moz tools to establish your real competitive baseline — do not rely on category generalizations when making investment decisions.

Page Authority Limitations: What PA Cannot Tell You

As valuable as Page Authority is as a benchmarking signal, it has hard structural limitations every SEO must understand to avoid misusing it. Treating PA as a comprehensive measure of ranking potential is one of the most common — and costly — SEO mistakes.

• ✗PA does not measure content quality. A page with thin, unhelpful, or even misleading content can have a very high PA if it has accumulated many authoritative links over time. Conversely, the most comprehensively helpful, expert-written page in your niche will have low PA if it lacks backlinks — regardless of how good it is.
• ✗PA does not measure keyword relevance or topical alignment. A page can have PA 72 for a topic it barely covers. PA reflects link equity strength, not how well a page matches a specific search query or demonstrates topical expertise in a given domain.
• ✗PA does not capture on-page or technical SEO signals. Page speed, Core Web Vitals, mobile usability, schema markup, title tag optimization, internal heading structure — none of these factor into PA whatsoever. A technically broken page with great links will still score high PA.
• ✗PA does not account for Google’s user experience signals. Click-through rate, dwell time, bounce rate, and other behavioral signals that Google may incorporate into its ranking evaluation are completely invisible to PA. A high-PA page with terrible UX can still underperform its PA score suggests.
• ✗PA is Moz-specific and not interchangeable with other tools. Ahrefs URL Rating, Semrush Authority Score, and Majestic’s Trust Flow each measure page-level authority differently. Comparing a page’s Moz PA against its Ahrefs UR as if they were the same metric will produce misleading conclusions.
• ✗PA is not a Google ranking factor. You can improve your PA substantially and see zero ranking change if your content doesn’t satisfy search intent, if your page has significant technical issues, or if your on-page optimization is inadequate. PA tells you about one component of ranking potential — it is not a complete ranking prediction.

The most effective SEO practitioners treat Page Authority as one signal inside a broader multi-factor evaluation framework. Use PA alongside content quality assessment, search intent analysis, on-page optimization audits, keyword difficulty scores, and technical SEO health checks. No single metric captures the full complexity of Google’s ranking system — not PA, not DA, not any third-party metric. Triangulate across signals for accurate analysis.

Frequently Asked Questions About Page Authority

The Bottom Line on Page Authority

Page Authority is Moz’s machine-learning-based score that predicts how likely a specific URL is to rank in Google search results. It’s built from dozens of link-based signals — primarily the quantity, quality, trustworthiness, and diversity of inbound backlinks — and compressed onto a logarithmic 1–100 scale. It is a relative, index-wide metric that shifts as the broader web evolves and as Moz periodically retrains its model against fresh Google SERP data.

The most strategic way to use Page Authority is always as a competitive benchmarking tool: assess SERP difficulty before targeting keywords, prioritize link outreach by source PA, identify your highest-PA internal linking hubs, monitor competitor PA trends, and close small authority gaps first for the fastest ranking gains.

Focus your efforts on earning authoritative backlinks from diverse, high-quality sources, maintaining a clean link profile, building a smart internal linking architecture, creating content worth citing organically, and consolidating fragmented link equity through 301 redirects. Page Authority will follow. Just remember — PA is a means to better rankings, not an end in itself. It measures one dimension of ranking potential in a search ecosystem driven by dozens of interconnected signals. Use it well, use it consistently, and always use it in context.