The free Domain Authority Checker looks up how well linked a website is. When Moz is answering, the tool returns the domain's Domain Authority and Page Authority scores, along with its spam score and the number of linking domains, and Moz is the company that created these metrics. When Moz is not answering, the tool shows a free rank from the Common Crawl web graph instead and says so on the result, because that rank is a different measure and is not Domain Authority or Page Authority. Each domain's result is cached for up to an hour, so checking the same domain again within that time shows the same numbers.
Domain Authority, or DA, is a score from 1 to 100 developed by Moz that predicts how well a website is likely to rank in search results. A higher score suggests greater ranking strength. It is a comparative measure, most useful for weighing one site against another or tracking a site over time, rather than an official ranking factor used by search engines.
How to Check Domain Authority
- Enter a domain. Type the domain you want to check, such as example.com. If you paste a full address, the tool keeps only the registered domain, so a page path and any subdomain, including www, are dropped. International names are converted to their ASCII form first. An IP address is not accepted, because authority belongs to a registered domain.
- Click Check Authority. The tool asks Moz for the domain's metrics and, if Moz is not answering, shows the Common Crawl rank instead.
- Read the result. A Moz result shows Domain Authority, Page Authority, spam score and linking domains. A Common Crawl result shows a rank score from 0 to 100, the domain's global rank, its PageRank position and the number of known hosts, with a note that names the source.
Understanding the Scores
Each number tells you something different. Domain Authority estimates the ranking strength of the whole domain, while Page Authority does the same for a single page, which in this tool is the home page of the domain you enter. The spam score flags characteristics Moz associates with sites that risk penalties, so a high spam score is a warning sign. Linking domains counts how many separate websites link to the site, a signal of its backlink profile. Read together, these give a quick picture of a site's authority and link health. The Common Crawl rank works differently: its score places the domain among roughly 135 million domains in Common Crawl's web graph, so a higher score means a better position. It covers domains only, with no page score, spam score or linking domain count, and small or new sites are often missing from it.
What Domain Authority Is, and Is Not
It is important to be clear about what this score means. Domain Authority is Moz's metric, not Google's, and Google does not use a Domain Authority score to rank pages. DA is a useful third-party estimate built from link data, best used for comparison: is this site stronger than that one, is my score rising over time, how do I compare to competitors. A high DA does not guarantee top rankings, and a lower DA does not prevent them. Treat it as one helpful signal among many, not as a verdict from the search engines themselves. Our guide to page authority vs domain authority goes through what each score measures. For the steps and what each kind of result means, see our guide on how to check domain authority and read the result.
When to Check Domain Authority
- Sizing up a competitor. Compare a rival site's ranking strength against your own.
- Evaluating a link opportunity. Gauge the authority of a site you might want a backlink from.
- Tracking progress. Watch your own score over time as you build links and content.
- Vetting a domain. Check how well linked a domain is before acquiring it, and its spam score when Moz is answering.
Related SEO Tools
To dig into a site further, run a full SEO score check, look up its domain age, or check its hosting and registrar.
