Domain Authority (DA) is one of the most talked-about numbers in SEO — and one of the most misunderstood. Site owners obsess over improving it, agencies report it as a primary KPI, and many people believe it directly influences Google rankings. Most of that is wrong. Here is what Domain Authority actually is, what it measures, and when it is genuinely useful versus when it is a distraction.
Who created Domain Authority and what does it actually measure?
Domain Authority was created by Moz, an SEO software company. It is a proprietary metric scored on a scale of 1 to 100. The score is calculated using a machine learning model trained to predict ranking ability, based primarily on the number and quality of backlinks pointing to the domain.
A Domain Authority score attempts to answer: based on this website's backlink profile, how likely is it to rank well compared to other sites? It is a comparative metric — a DA of 40 is only meaningful when compared to a competitor's DA of 25 or 60.
Moz updates DA scores regularly. Because the score is recalibrated against the entire web, your DA can drop even when you are actively building good links — simply because other sites in the index have grown their backlink profiles faster.
Does Google use Domain Authority to rank websites?
No — Google does not use Moz's Domain Authority in its algorithm. Google has never used it and has stated this multiple times. Domain Authority is entirely a Moz creation. What Google does use is its own internal assessments of a site's link authority and trustworthiness — sometimes called PageRank (still used internally), domain trust, and various other quality signals. These are related concepts to DA, but they are not the same metric.
What is the difference between Domain Authority and Domain Rating?
Domain Authority (DA) is Moz's metric. Domain Rating (DR) is Ahrefs' equivalent metric. Both attempt to measure the strength of a website's backlink profile, and both score from 0 to 100. They use different data sources and different calculation methods, so the same site will often show quite different scores between the two tools.
Neither is more correct than the other — they are both approximations of underlying backlink authority using that company's particular index of the web. When evaluating competitor sites, consistency matters more than which tool you use. Pick one and compare consistently within it.
When is Domain Authority actually useful?
Despite not being a Google signal, DA is genuinely useful in two specific situations:
Comparing competitors at a glance. If you are evaluating whether a keyword is realistically rankable for your site, comparing your DA to the top-ranking competitors gives a rough sense of how the backlink authority gap looks. A site with DA 20 competing against results dominated by DA 70+ sites has a significant authority gap to close before realistic ranking is possible.
Qualifying link prospects. When deciding which sites to prioritise for link building outreach, DA (or DR) helps filter out obviously low-value prospects. A link from a DA 50 site in your niche is worth considerably more effort than a link from a DA 5 one.
Should you try to improve your Domain Authority score?
Not as a goal in itself. The actions that improve DA — earning high-quality editorial backlinks from relevant, authoritative sites — are exactly the right link building activities anyway. Do those things and your DA will improve naturally as a side effect. But buying links, submitting to hundreds of directories, or using link schemes to artificially inflate your DA score creates the appearance of authority without the substance that actually helps rankings.
What does Google actually use instead of Domain Authority?
Google uses multiple internal signals that relate to link authority, none of which are publicly disclosed as a single score. What Google has confirmed over the years includes:
- PageRank — the original link authority signal, still used internally but no longer publicly visible
- Trust signals — how trustworthy Google considers a domain based on the quality of sites linking to it
- Relevance signals — how topically relevant the linking sites are to your content
- Site quality classifiers — machine learning models assessing overall site quality including the Helpful Content classifier
- E-E-A-T signals — the Experience, Expertise, Authoritativeness, and Trustworthiness framework discussed in our guide to building E-E-A-T
What is a good Domain Authority score?
There is no universally "good" DA score — it entirely depends on your competition. A DA of 35 is excellent if you are competing in a niche where most competitors have DA 15–25. The same score of 35 is very weak if you are targeting keywords where the top results belong to DA 70–85 national publications.
The only meaningful DA benchmark is your direct keyword competitors. Use our anchor text analyser alongside Moz's free Link Explorer to compare your backlink profile against the sites currently ranking for your target keywords.
Summary
- Domain Authority is a Moz metric scored 0–100 that estimates ranking potential based on backlink profiles — it is not a Google signal
- Google does not use DA in its algorithm and has confirmed this repeatedly
- DA is useful for competitor comparison and link prospect qualification — not as a standalone goal
- Improving DA as a side effect of good link building is fine; gaming DA with artificial links is not
- What Google actually uses is its own undisclosed internal authority signals including PageRank, trust signals, and quality classifiers
- Always evaluate DA relative to your actual keyword competitors — an absolute score means nothing without context
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