Domain Authority

How Moz Calculates Domain Authority

Moz does not publish the exact formula for Domain Authority. The company says it uses a machine learning model trained on link data from its index — see also Caspian Wilder’s guide to raising Domain Authority.

The main inputs are the number of unique linking root domains and the quality of those links. Moz also considers link relevance and spam signals.

Because DA is a relative score, your site's number can change when Moz re-indexes the web or updates its algorithm. A score of 50 today may mean something different next year.

You can check your DA using the free Mozbar browser extension or the Moz Link Explorer tool.

For example, a new site with few backlinks may start with a DA of 10–20, while a well-established news site can reach 90+. The score is logarithmic, meaning it gets harder to increase as you go higher.

Moz also accounts for link quality through its proprietary spam score, which penalises links from low-quality domains.

What Domain Authority Is Not

Domain Authority is not a Google ranking factor. Google has stated that it does not use DA or any third-party metric in its search algorithm.

It is also not a measure of site quality, traffic, or content relevance. A site with high DA can still have poor content or low visitor numbers.

Do not compare DA scores across different tools. For example, what domain rating ahrefs means uses a different scale from Moz's DA. Authority Score from Semrush also has its own inputs and formula.

Each vendor's metric is an estimate. Only Google knows its ranking algorithm.

DA does not measure brand authority, user trust, or the likelihood of a click. A high-DA site can still have high bounce rates if its content is poor.

It also does not reflect social media influence or offline reputation. For instance, a site that buys links may temporarily boost its DA but still rank poorly because Google ignores those signals.

• DA is not a Google metric — treat it as a vendor estimate.
• DA does not measure content quality or user experience.
• DA scores from different tools are not interchangeable.

How to Use Domain Authority in SEO

SEO professionals use DA mainly for link building. When evaluating a potential link partner, a higher DA often suggests a stronger backlink profile.

You can also use DA to benchmark your site against competitors. If your DA is 35 and a rival is 50, you may need more high-quality links to close the gap.

Track your own DA over time to see if your link-building efforts are working. A steady increase indicates you are gaining authoritative links.

Remember that DA is just one signal. Always check a site's relevance, traffic, and spam risk before pursuing a link. For a broader view, read about SEO Authority.

Common Mistakes with Domain Authority

Many beginners treat DA as a direct ranking factor. This leads to chasing a number instead of building real authority through good content and relevant links.

Another mistake is comparing DA scores from different tools. Each vendor uses its own data and formula, so a DA of 40 from Moz is not the same as a Domain Rating of 40 from Ahrefs.

Some people try to inflate DA by buying low-quality links. This can backfire if Google penalises the site, hurting rankings and traffic.

Finally, using DA alone to judge link quality ignores relevance. A link from a high-DA site in an unrelated niche may pass little value.

Domain Authority vs Other Authority Metrics

Several SEO tools offer their own authority scores. The table below compares the most common ones.

Each metric uses different data sources and scales. None of them are official Google signals.

For historical context, DA is loosely inspired by what pagerank means, but Google's original PageRank is no longer public.

For example, a site with many links from low-quality domains may have a high Domain Rating but a low Domain Authority, because Moz's model penalises spam. Conversely, a site with fewer but high-quality links could have a higher DA than DR.

Always check the underlying backlink profile rather than relying on a single number.

How to Improve Your Domain Authority

Improving DA takes time and consistent effort. Focus on earning high-quality backlinks from relevant, authoritative sites.

Create content that people want to link to — original research, guides, or data-driven articles. Promote it through outreach and social media.

Avoid spammy link-building tactics like link farms or paid links. These can harm your site's reputation and may lead to a Google penalty.

Also ensure your site is technically sound. Fast load times, mobile-friendliness, and good internal linking support overall SEO health. For more on domain strategy, see SEO Domains.

To track your progress, use the Moz Toolbar or Moz's Link Explorer. Check your DA monthly, but do not obsess over small fluctuations.

• Earn links from relevant, high-authority sites.
• Create link-worthy content like original research.
• Avoid low-quality or paid link schemes.
• Monitor your DA monthly with Moz tools.