Domain Authority (DA)
A metric invented by Moz (not Google) that predicts how well a site will rank. Useful as a rough comparison tool, but don't obsess over it - Google doesn't use it.
Why It Matters
Domain Authority is the metric that launched a thousand misunderstandings. It's a score from 0-100 created by Moz to estimate a site's ranking potential based on its backlink profile. It's useful for quick competitive comparisons - but it is absolutely, categorically not a Google ranking factor.
The problem is that agencies sell DA increases as if they're selling ranking improvements. "We'll get your DA from 25 to 45" sounds impressive until you realise Google doesn't look at this number at all.
In Practice
Use DA as a rough benchmark when comparing sites in the same niche. A DA 60 site generally has a stronger backlink profile than a DA 20 site. It's a useful shorthand.
But don't optimise for DA specifically. Don't pay for services that promise to increase your DA. And don't use DA as your primary metric for link prospects - a DA 30 site in your exact industry is often more valuable than a DA 70 site with zero topical relevance.
If an agency reports on DA as a primary KPI, ask why they're not reporting on actual rankings, traffic, and conversions instead.
Common Mistakes
Treating DA as a ranking factor or a currency. It's a third-party metric that correlates with rankings - it doesn't cause them. Two sites with the same DA can rank completely differently for the same query. Watch the trend, don't worship the number.
Sources & Further Reading
Where to verify this yourself - Google's own documentation, industry reporting, and how we apply it at Underdog. Don't take our word for it; check the source.
Related Terms
Glossary
Domain Rating (DR)
Ahrefs' version of domain authority - measures backlink profile strength on a 0-100 scale.
Glossary
Backlink
A link from another site to yours - still one of Google's top ranking factors.
Glossary
PageRank
Google's original link-based algorithm for measuring page importance - still a factor.
Glossary
Link Equity
The ranking value passed through links from one page to another - also called link juice.
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