Searchlab Domain Authority Explained: What It Is, What It Isn't
Domain Authority (DA), Page Authority (PA), Spam Score, Moz Trust, these are Moz's predictive scores for how likely a page is to rank. Google doesn't use them directly, but they're a useful comparative shorthand for understanding link equity and site quality.
The 12 metrics and what they mean
- Moz Domain Authority (0 to 100). Predicts overall ranking strength of a domain. Higher is better.
- Moz Page Authority (0 to 100). Same idea but for a single URL.
- Semrush Authority Score. Similar predictive metric from Semrush. Different inputs, similar concept.
- Total / Quality / DoFollow / NoFollow Backlinks. The link graph that drives all the other scores.
- Spam Score (0 to 100%). Estimates the probability the site looks spammy. Higher = worse.
- Moz Trust. How trustworthy the linking neighbourhood is. Inverse of spam, basically.
- Off-page SEO Score. Composite of authority, backlinks, and trust signals.
- Domain Age. How long the domain has existed. Older domains tend to rank better, all else equal.
How to actually use these scores
- Set realistic targets. If your DA is 15 and you're chasing keywords where the top 10 all have DA 60+, you're going to lose. Pick lower-competition keywords.
- Track backlink growth, not just DA. DA is logarithmic, going from 30 to 35 is easy; 50 to 55 takes 10x the work.
- Compare to competitors. If your competitor's DA is 5 points higher and they outrank you, the link gap is the most likely cause.
- Watch your spam score. Above 30% and you should audit your backlink profile, you may have toxic links to disavow.
The honest truth: Google doesn't use DA. It uses its own internal score (called PageRank historically) and hundreds of other signals. DA is a third-party estimate that correlates with rankings, useful as a north star, not as an exact target.
Frequently asked
Why does my DA differ from Moz Pro's?
We use Open PageRank scaled to a 0 to 100 range as a proxy. It's free and gives similar relative rankings, but exact numbers may differ from Moz's paid DA.
What's a "good" Domain Authority?
Above 30 is solid for niche sites. Above 50 is strong. Above 70 is elite. Below 20 is normal for sites under 2 years old.
How do I increase DA?
Earn backlinks from high-DA sites. Genuine outreach, guest posting on real publications, and creating link-worthy content (data studies, free tools, comprehensive guides).