Moz Metrics
A family of third-party SEO scores developed by Moz — including Domain Authority, Page Authority, and Spam Score — that estimate a site's ranking strength on a 0–100 scale.
Moz Metrics is the umbrella term for the third-party SEO scores developed by Moz to estimate how well a website is likely to rank in search results. The most widely used Moz Metrics are Domain Authority (DA), Page Authority (PA), and Spam Score, all of which are scored on a logarithmic 0–100 scale where higher is stronger.
Domain Authority predicts how a whole domain will rank based on the size and quality of its backlink profile, the number of unique linking root domains, and a handful of smaller signals. Page Authority applies the same model to a single URL. Spam Score estimates how likely a site is to be penalized, expressed as a percentage of "spam flags" the site triggers. Moz also publishes smaller-used scores like MozTrust and MozRank, which feed into the others.
Moz Metrics are not Google ranking factors — Google's algorithm does not consume them. They are useful as a relative benchmark for comparing your site to competitors, for vetting link prospects, and for tracking authority trends over time. The scores update whenever Moz re-crawls the link graph, so they shift slowly and you should not expect them to change hour-to-hour. Free tools like the SERPView Free DA PA Checker (/tools/da-pa-checker) let you look up DA and PA for any domain without a Moz Pro subscription.