Domain Rating vs Domain Authority: How Ahrefs DR and Moz DA Differ
A travel blogger in Himachal checks her site on two tools on the same afternoon. Ahrefs says Domain Rating 41. Moz says Domain Authority 26. She assumes one of them is broken. Neither is. They are two different companies measuring two slightly different things with two different crawlers, and the gap between them is normal.
The short version
Domain Rating (DR) is Ahrefs' score for the strength of a website's backlink profile. Domain Authority (DA) is Moz's prediction of how well a site might rank. Both run from 0 or 1 to 100, both are logarithmic, and both are built from link data. Google uses neither.
| Domain Rating (DR) | Domain Authority (DA) | |
|---|---|---|
| Made by | Ahrefs | Moz |
| What it tries to express | Strength of the backlink profile | Predicted ranking ability |
| Main inputs | Unique linking domains with followed links, and the DR of those domains | Link signals from Moz's index fed into a machine learning model |
| Data source | Ahrefs' crawler and index | Moz's crawler and index |
| Uses traffic? | No | No |
How Domain Rating is calculated
Ahrefs has been fairly open about the logic. DR looks at how many unique domains link to a site with followed links, and how strong those linking domains are by their own DR. A linking domain's influence is also split across all the sites it links out to, so a link from a strong site that links to very few domains passes more of its weight than the same link from a site that links to thousands.
Multiple links from one domain count once. Nofollow links don't count. Content quality, traffic and spam signals are not part of the formula.
That makes DR easy to reason about. If a site's DR jumps, it almost always means it gained followed links from new, reasonably strong domains.
How Domain Authority is calculated
Moz's Domain Authority takes link data (linking root domains, total links and other features) and runs it through a model trained to predict where sites appear in Google results. Moz has said this approach, introduced with DA 2.0 in 2019, is designed to make the score harder to inflate with spammy links than a simple link count would be.
Because DA tries to predict rankings rather than describe link strength, it can treat two sites with similar link counts differently based on patterns the model has learned.
Why the two numbers disagree
Most gaps come down to three causes.
Different indexes. Each tool crawls the web on its own. If Ahrefs has found 180 domains linking to the travel blog and Moz has found 95, the scores will differ before any maths happens.
Different formulas. DR is a direct function of linking domains and their strength. DA is a model output. A site with a few links from very strong domains may look better in DR than in DA.
Different calibration. A 40 in one tool is not supposed to equal a 40 in the other. The scales are separate. Comparing DR 41 with DA 26 is like comparing a score out of 100 in two different exams.
Which one should you use
Use the one you have access to and use it consistently. Switching between tools from month to month produces noise that looks like progress or decline.
Some practical guidance:
- For your own reporting, pick one metric and track it alongside clicks and referring domains from Search Console.
- For link prospecting, use either score as a first filter, then look at traffic and relevance by hand. A DR 70 site with no organic visitors is worse than a DR 30 niche site with real readers.
- For client conversations, explain which tool you used. Agencies sometimes show DR in one report and DA in the next, and clients understandably panic when the number "drops" by 15.
If you have access to both, use the disagreement as information. A site with a DR far above its DA, and no traffic to match, sometimes means it has picked up links from domains that exist mostly to pass DR. That pattern shows up a lot in sites that sell guest posts.
How each metric gets gamed
DR's transparency is also its weakness. Since it counts followed links from strong domains and weighs them by how few outbound links those domains have, link sellers can manufacture DR through networks of sites that link to each other sparingly. Expired domains with old strong links are another shortcut.
DA is harder to push with obvious tricks, but not immune. Large volumes of links from sites with decent DA still raise it.
Neither score detects whether a link was paid for. That judgement is yours. Google's spam policies describe buying links to pass ranking credit as a link scheme, and an inflated authority score can make a risky site look safe at a glance. Our guide on how to check backlink quality covers the manual checks that catch what the numbers miss.
Other metrics you will run into
Semrush has its own Authority Score, which combines link data with organic traffic estimates and spam signals. Majestic uses Trust Flow and Citation Flow, which separate link quantity from link trustworthiness. Each tool has its own index, so the same site will score differently again.
None of these is the "real" authority of a site. Google has its own internal signals and does not publish them.
A sensible way to work with both
When you vet a prospect, open a spreadsheet with these columns: domain, DR, DA, estimated organic traffic, topic match (yes or no), and a notes field for anything odd. Fill it in for your next 20 link prospects. Within a few rows you'll see which sites have scores that match their real presence and which ones are numbers without an audience, and that pattern will tell you more than either metric alone.