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Domain Authority: What It Is and Why

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Domain Authority: What It Is and Why

“Domain Authority” is one of the most discussed SEO metrics. But it’s also one of the most misunderstood.

First, the important clarification: Domain Authority isn’t a Google metric. Google doesn’t share a public “authority score.” What we call domain authority are third-party estimates of how well a site might rank.

Understanding what these metrics actually measure—and their limitations—helps you use them effectively.

The History: PageRank

Google’s original ranking algorithm was PageRank, named after Larry Page. It assigned scores based on links:

  • More links = higher score
  • Links from high-PageRank pages = more valuable
  • A page’s authority flowed to pages it linked to

Google stopped publishing PageRank scores in 2016, but the concept remains central to their algorithm.

Third-Party Authority Metrics

Various SEO tools created their own metrics to estimate authority:

Moz Domain Authority (DA)

  • Scale: 1-100
  • Based on: Moz’s link index
  • Updates: Monthly

Ahrefs Domain Rating (DR)

  • Scale: 0-100
  • Based on: Ahrefs’ link index
  • Updates: Daily

Semrush Authority Score

  • Scale: 0-100
  • Based on: Multiple factors including links, traffic, spam signals

Open PageRank

  • Scale: 0-10
  • Based on: Common Crawl data
  • Free and open access

Each uses different methodologies, so scores don’t translate directly between tools.

What Authority Metrics Measure

At their core, these metrics estimate:

  1. Quantity of backlinks: How many sites link to you
  2. Quality of backlinks: How authoritative are those linking sites
  3. Link diversity: How many unique domains link to you

Some also incorporate:

  • Traffic estimates
  • Spam signals
  • Age of links

What Authority Metrics Don’t Measure

These metrics have significant limitations:

No Topical Relevance

A link from a random high-authority site counts the same as a link from a highly relevant site in your industry. Google likely weighs relevance heavily.

No Content Quality Signal

Authority metrics don’t assess whether your content is actually good. A domain could have high authority from historical links while current content is poor.

No User Experience Factor

Page speed, mobile-friendliness, and UX don’t factor into link-based authority scores.

Manipulation Vulnerability

Because they’re based on links, these metrics can be artificially inflated through link schemes. High authority doesn’t guarantee a trustworthy site.

Interpreting Authority Scores

Relative, Not Absolute

A DA of 50 means nothing in isolation. Compare against:

  • Competitors in your space
  • Sites ranking for your target keywords
  • Your historical scores

Not Linear

Going from 20 to 30 is easier than going from 70 to 80. The scale is logarithmic—higher scores require exponentially more effort.

Industry Context Matters

Some industries naturally have more links:

  • News sites: Very high authority
  • Local businesses: Typically lower authority
  • SaaS products: Varies widely

A DA of 40 might be excellent in one niche and mediocre in another.

How to Check Authority

Moz, Ahrefs, and Semrush offer the most comprehensive data, but require subscriptions.

Free Options

Open PageRank provides free access based on Common Crawl data.

Our Domain Authority Checker uses Open PageRank to show:

  • PageRank score (0-10 scale)
  • Global ranking
  • Authority tier classification

It’s free and gives you a quick benchmark.

Improving Authority

Authority is essentially a proxy for “how many quality sites link to you.” Improving it means earning better links.

Create Link-Worthy Content

Content that naturally earns links:

  • Original research and data
  • Comprehensive guides
  • Tools and calculators
  • Unique insights or perspectives
  • Visual assets (infographics, charts)

Build Relationships

Links often come from relationships:

  • Industry connections
  • Guest posting (legitimate, not mass-produced)
  • Interviews and podcasts
  • Collaborative content

Ways to earn editorial links:

  • HARO (Help a Reporter Out)
  • Expert roundups
  • Industry publications
  • Award submissions

Fix Technical Issues

Ensure links work:

  • No broken pages (404s)
  • Proper redirects
  • Consistent URL structure

Find mentions without links:

  • Brand mentions
  • Image usage
  • Data citations

Reach out and request links be added.

Authority vs. Rankings

Here’s the key insight: authority is correlated with rankings but doesn’t cause them.

Sites with high authority tend to rank well because:

  • They’ve earned links through quality content
  • Their content is likely good (it attracted links)
  • They’ve been around long enough to accumulate links

But you can’t buy authority (through link schemes) and expect to rank. Google is sophisticated enough to detect and penalize manipulative link building.

Focus on:

  1. Creating excellent content
  2. Promoting it so it earns natural links
  3. Building genuine industry relationships

Authority will follow.

When Authority Matters Most

Competitive Analysis

See how you stack up against ranking competitors. Big authority gap? You’ll need more links or a different keyword strategy.

Prioritize outreach to higher-authority sites—links from them are more valuable.

Monitoring Progress

Track authority over time as a proxy for link building success.

Due Diligence

Evaluating potential partners, acquisition targets, or vendors? Authority indicates their online presence and credibility.

Common Misconceptions

”I need to reach DA 50”

There’s no target that guarantees rankings. Many sites rank well with lower authority through excellent content and topical relevance.

”Authority is permanent”

Authority fluctuates. Links disappear, algorithms change, competitors grow. It requires ongoing effort.

”High authority = trustworthy”

Not necessarily. Link schemes can inflate authority. Evaluate sites holistically.

Low-quality links can be ignored or even harmful. A few great links beat many mediocre ones.

Take Action

  1. Check your current authority with Domain Authority Checker
  2. Benchmark against competitors
  3. Identify your best content for link building
  4. Develop a relationship-building strategy
  5. Monitor progress over time

For help with link building strategy or SEO, reach out.