There’s no single “website authority”
Google doesn’t use any third-party authority score. Its guide to its ranking systems lists PageRank and other link analysis among its core systems and names no vendor’s metric, and Moz says its own Domain Authority is not a Google ranking factor. So an authority checker can only show what a vendor estimates about a site’s links or popularity, from its own data and its own formula.
The four signals
- Domain Rating (Ahrefs), 0 to 100. The strength of a site’s backlink profile compared with other sites in Ahrefs’ database, on a logarithmic scale. For one site in depth, use the Domain Rating checker. For a list, use the bulk checker.
- Backlinks and rank (DataForSEO). Referring domains and total backlinks from DataForSEO’s link index, plus its rank, a PageRank-style score shown on a 0 to 100 scale. DataForSEO says its rank and Ahrefs’ DR use different methods, so their values aren’t expected to match.
- Popularity (Tranco), rank 1 to 1,000,000. Where the domain sits in the Tranco top million, a list that averages several popularity rankings over 30 days. It measures visitors, not links, and lower is more popular.
- Domain age (RDAP). When the current registration began, from the registry’s public record.
We don’t add these into one number. They measure different things from different data, so any weighting would be invented.
On DataForSEO’s own notes, a rank of 200 to 300 on its 0 to 1000 scale, about 31 to 45 on the 0 to 100 scale used here, is typical of large domains with many links from authoritative pages, and 500 and up, about 71 and above, of huge domains.
How to use them
Comparing link prospects. Check three to five candidates and look for agreement. A site with a solid DR, a few hundred referring domains and a Tranco rank is probably real. A high DR with no Tranco rank and a domain registered last year deserves a closer look. That’s a rule of thumb, not a verdict.
Sizing up a competitor. Referring domains show how many separate sites link to them. Compare that with your own count and with the pages that rank for your keywords, then see what those links earn in the website traffic checker.
Limits
Every index is different, so counts rarely match between tools, and none match what Google sees. Link networks can inflate any of these scores. Treat a number as a prompt to look at the site, not as a goal. More in our entry on domain authority.