What Is the Relationship Between Link Score and Other Link Metrics Such as PageRank or Domain Authority?


The relationship between link score and other link metrics such as PageRank or domain authority lies in their common goal of evaluating the quality and influence of a webpage or domain's backlinks. Link score is a general term that may refer to different proprietary algorithms used by various SEO tools to assess link quality. PageRank, introduced by Google, measures the importance of web pages based on incoming links. Domain authority, developed by Moz, predicts how well a domain will rank on search engines based on multiple link-related factors. Here’s an in-depth exploration of these metrics and their interrelationship.

A link score typically represents a metric used by SEO tools to evaluate the quality and potential impact of a backlink. Various tools employ unique algorithms to calculate this score, considering factors such as link relevancy, authority of the linking site, and link placement.

Example: Ahrefs' URL Rating (UR)

Ahrefs, a popular SEO tool, uses URL Rating (UR) to measure the strength of a target URL’s backlink profile. The score ranges from 0 to 100, with higher scores indicating stronger backlink profiles.

Read more about URL Rating on Ahrefs’ website: [URL Rating (UR) - Ahrefs]

The Concept of PageRank

PageRank, developed by Google co-founders Larry Page and Sergey Brin, evaluates the importance of web pages based on the quantity and quality of backlinks. It uses an algorithm that iteratively distributes a rank score among pages based on their incoming links, considering both the number and the PageRank of these links.

PageRank Algorithm

The core idea is that a page linked to by many other pages (particularly those with higher PageRank) is considered more important:

  • A link from a high-PageRank page transfers more PageRank than a link from a low-PageRank page.
  • PageRank is distributed equally among all outbound links on a page.

Read the original paper by Page and Brin: [The Anatomy of a Large-Scale Hypertextual Web Search Engine, 1999]

Domain Authority (DA) by Moz

Domain Authority (DA) is a metric created by Moz to predict how well a website will rank on search engine result pages (SERP). It is scored on a scale from 1 to 100, with higher scores indicating a better ability to rank.

Factors Influencing Domain Authority

DA is calculated using dozens of factors, but primarily relies on the following link metrics:

  • Link quality: The prevalence of high-quality, authoritative backlinks.
  • Link quantity: A larger number of backlinks can contribute positively, though quality prevails over sheer quantity.
  • Link diversity: A diverse range of unique linking domains signals a robust backlink profile.

Learn more about DA on Moz: [Domain Authority (DA) - Moz]

Common Goals

All these metrics - link score, PageRank, and Domain Authority - aim to identify the influence and quality of backlinks, helping determine the potential of a webpage or domain to rank well on SERPs.

Complementary Insights

Each metric provides a different perspective. For instance:

  • PageRank focuses on the algorithmic importance of individual pages based on the link structure of the web.
  • Domain Authority evaluates the overall potential of an entire domain to rank, factoring in a broader set of link-related signals.
  • Proprietary link scores from tools like Ahrefs or SEMrush offer additional proprietary insights, often incorporating more recent algorithm updates and factors.

Practical Usage

For SEO practitioners, understanding and leveraging multiple link metrics can provide a comprehensive view of a site's backlink profile and ranking potential.

Example: Using:

  • Ahrefs’ URL Rating to assess the strength of individual backlinks.
  • Moz’s Domain Authority to gauge overall domain strength and SERP potential.
  • PageRank concepts to understand link distribution and value flow.


The interaction between link score, PageRank, and Domain Authority highlights different aspects of link quality and influence, each playing a pivotal role in determining a site's ranking potential. Utilizing a combination of these metrics can offer a holistic understanding and guide effective SEO strategies.