Domain Authority Checker Tool What is Domain Authority? Domain Authority represents Moz’s best prediction for how a website will perform in search engine rankings & Google search results. Use Domain Authority when comparing one site to another or tracking the “strength” of your website over time. How is Domain Authority Scored? Domain Authority on a 0-100 in logarithmic scale like PageRank, Thus, it’s easier to grow your score from 20 to 30 than it would be to grow from 70 to 80.