Who makes it
Domain Authority is Moz's metric. Other SEO tools have similar scores, like Ahrefs' Domain Rating and Semrush's Authority Score. Each is calculated differently, so the numbers aren't interchangeable.
Is it a Google ranking factor?
No. Google doesn't use Domain Authority or any third-party score. These metrics try to predict ranking strength from link data, which makes them useful for comparing sites, but they aren't what Google measures.
How to use it sensibly
Use it to compare your site with competitors or to judge whether a site is worth getting a link from. Don't treat raising the number as a goal. Earning relevant links and publishing strong content tends to raise it as a side effect.
Why Domain Authority matters
Domain Authority is a quick way to size up the competition for a search. If every top-ranking page sits on a much stronger site, you know you'll need more links and better content to compete, or a more specific search to target.
Picking winnable searches
A new site finds that the top results for a broad term all belong to large, well-linked publishers. It targets narrower, more specific searches where the ranking pages come from smaller sites, and wins those first while building links over time.
Common mistakes
Chasing the score itself
Buying links or using shortcuts to raise a score can violate Google's spam policies and doesn't help real rankings.
Comparing different tools' numbers
A DA of 40 and a DR of 40 don't mean the same thing. Compare sites using the same tool.
Ignoring page-level strength
A strong page on a modest site can outrank a weak page on a big site. Look at the specific pages competing for a search, not just the domain.
Where we work on this