Domain Authority (DA) is a score from 0 to 100 that predicts how likely a domain is to rank in search engine results. It was created by Moz and is now also calculated by DataForSEO. The score is based on a domain's backlink profile, including how many sites link to it, how authoritative those linking sites are, and how diverse the link sources are.
How Domain Authority is calculated
DA uses a machine learning model trained on real search results. It looks at the number of referring domains, the quality of those links, and dozens of other signals to land on a single number. A brand new domain starts at DA 1. Major sites like Wikipedia or Google sit above 90. Most expired domains you'll encounter fall between 10 and 50.
The scale is logarithmic. Going from DA 20 to 30 is much easier than going from 60 to 70. And it's relative — your DA only matters compared to the sites you're competing against in search results.
One thing to keep in mind: DA is not a Google metric. Google doesn't use it in their algorithm. But it correlates well with ranking ability because it measures the same thing Google cares about: backlink quality and quantity.
Why DA matters for expired domains
When you buy an expired domain, you're buying its link profile. A domain with DA 35 and 200 referring domains carries real authority that took years to build. You can use that authority through a 301 redirect or by building a new site on the domain.
But DA alone doesn't tell the full story. A domain with DA 40 and spammy links is worse than one with DA 20 and clean, relevant backlinks. Always check Trust Flow and the actual link sources alongside DA.
Domain Authority on CatchDoms
CatchDoms displays DA in a dedicated column for every domain, pulled from DataForSEO's API. You can filter domains by minimum DA using the da_min filter to focus on higher-authority names. Along with TF, backlinks, and domain score, DA helps you quickly spot the domains worth investigating further.