What is Domain Authority?

Domain Authority (DA) is a search engine ranking score developed by Moz that predicts how well a website will rank on search engine result pages (SERPs). A Domain Authority score ranges from one to 100, with higher scores corresponding to a greater ability to rank.
Domain Authority is calculated by evaluating multiple factors, including linking root domains and number of total links, into a single DA score. This score can then be used when comparing websites or tracking the “ranking strength” of a website over time. Domain Authority is not a metric used by Google in determining search rankings and has no effect on the SERPs.
You can use Link Explorer to check Domain Authority, or view a website’s DA by using MozBar (a free Chrome-extension), the SERP Analysis section of Keyword Explorer, and dozens of other SEO tools across the web.

How is Domain Authority scored?

We score Domain Authority on a 100-point logarithmic scale. Thus, it’s significantly easier to grow your score from 20 to 30 than it is to grow from 70 to 80.

What is a “good” Domain Authority?

Generally speaking, sites with a very large number of high-quality external links (such as Wikipedia or Google.com) are at the top end of the Domain Authority scale, whereas small businesses and websites with fewer inbound links may have a much lower DA score. Brand-new websites will always start with a Domain Authority score of one.
Because Domain Authority is meant to be a predictor of a site’s ranking ability, having a very high DA score shouldn’t be your only goal. Look at the DA scores for the sites you’re directly competing with in the SERPs and aim to have a higher score than your competitors. It’s best used as a comparative metric (rather than an absolute, concrete score) when doing research in the search results and determining which sites may have more powerful/important link profiles than others. Because it’s a comparative tool, there isn’t necessarily a “good” or “bad” Domain Authority score.