Domain Authority
Last updated September 2026
Domain Authority (DA) is a third-party metric, developed by Moz, that scores a website's likely ability to rank on a 1-to-100 logarithmic scale based on its link profile. It is not a Google ranking factor; it is a comparative estimate used to gauge relative competitive strength between sites.
Domain Authority is one of the most quoted numbers in SEO and one of the most misunderstood. Moz built it as a predictive score, based primarily on the quantity and quality of links pointing to a domain, meant to estimate how competitively a site could rank against others. It is not published or used by Google, and third-party scores like Ahrefs' Domain Rating work the same way: neither plays any role in actual search rankings.
01
What DA actually measures
The score is calculated from Moz's own link index using a machine-learning model trained to correlate with search performance. It is logarithmic, so moving from 20 to 30 is a much smaller lift than moving from 70 to 80, and the score is only meaningful relative to other domains scored by the same tool. A DA of 40 does not mean anything fixed on its own; it means something when compared to the DA of the sites it competes against in the search results.
02
Why clients fixate on it anyway
DA is popular precisely because it is easy to check with a free tool and easy to explain in a slide. That makes it a common yardstick clients bring to a review, even though it correlates with ranking strength rather than causing it. A site can carry a high DA and still lose rankings to a lower-DA competitor with better content and stronger topical relevance.
- 01
DA is a Moz metric, not a Google signal; Ahrefs and Semrush publish their own similarly-named but differently-calculated equivalents (DR, Authority Score), each rooted in the site's off-page link profile
- 02
Scores from different tools are not directly comparable to each other
- 03
DA tends to move slowly and is a lagging indicator, not something to chase week to week
- 04
A rising DA with flat rankings usually means the link growth is not topically relevant to what the site is trying to rank for
03
Setting expectations with clients
For an agency reporting to a client, DA is best used as directional context rather than a KPI. Rankings, organic traffic, and conversions are the metrics that reflect actual performance; DA is a useful proxy for competitive link strength but a poor stand-in for progress. Framing it that way early prevents a client from expecting a monthly DA jump the way they might expect a ranking or traffic improvement.
Where this applies
