Domain Rating vs Domain Authority: what each score means and when to use it

Domain Rating (DR) is Ahrefs' measure of how strong a domain's backlink profile is. Domain Authority (DA) is Moz's machine-learning prediction of how well a domain will rank in search results, trained on Moz's own link data. Both run 0–100 and both are built from links, but they use different crawlers, different indexes and different maths — so the same site routinely scores several points apart on the two scales.

No, and they are not interchangeable. They are competing proprietary metrics from two competing SEO companies, each computed from that company's own crawl of the web. There is no official conversion between them and no reason to expect one. The most common analysis error in link building is comparing your DR to a competitor's DA and drawing a conclusion from the gap — the gap is mostly an artefact of the two indexes disagreeing about which links exist.

Neither, because there is nothing external to be accurate against. Google has never published a domain-level authority score, and Google representatives have repeatedly said there is no single site-wide authority value used the way these metrics imply. DA and DR are both estimates designed for comparison between sites, not reproductions of anything inside Google's ranking systems. The practical answer is to pick whichever one your team already has data for and use it consistently.

Because the two companies see different webs. Ahrefs and Moz run separate crawlers with separate budgets and separate refresh cycles, so each one has discovered a different subset of the links pointing at you. On top of that, DR is a fairly direct function of the link graph while DA is the output of a model trained to predict rankings, which adds its own weighting. A 5–15 point spread is entirely normal and is not a sign that either number is broken.

There is no reliable conversion, and any converter offering one is fitting a curve to noise. The relationship between the two scores varies by niche, by site age and by link profile shape — a site with many low-quality links can score very differently on the two scales than a site with fewer editorial links. If you need both numbers, measure both: check DR through Ahrefs' free Domain Rating endpoint and DA through Moz Link Explorer, and never derive one from the other.

Not through an API. Moz exposes Domain Authority only through the paid Moz Links API, which requires an access token, so no free tool can return a genuine DA figure programmatically. Moz's own Link Explorer gives you a limited number of free lookups through its web interface with an account, and that is the legitimate free route to your literal DA. Domain Rating is the opposite case: Ahrefs publishes a genuinely free, keyless Domain Rating endpoint, which is why free DR checkers work and free DA checkers generally do not.

Only loosely, and never at the page level. Both metrics describe a domain's links and nothing else — not intent match, not content depth, not internal linking, not freshness. A DR 30 page written precisely for the query regularly outranks a DR 70 page that only glances at it. Use authority scores to size the link-building gap between you and the sites you compete with, then win on the factors that actually differ page by page.

Use one metric consistently across every site in the analysis. The comparison is what carries the information — a competitor at DR 62 against your DR 38 tells you something real, while a competitor's DA 55 against your DR 38 tells you almost nothing. If you have access to both tools, run both and compare each metric within its own column. If you only have one, that one is sufficient for benchmarking.

They are the page-level companions to DR and DA respectively: URL Rating (UR) is Ahrefs' strength score for a single URL, and Page Authority (PA) is Moz's ranking prediction for a single page. They matter more than the domain scores for individual ranking decisions, because a strong domain can host a page that has earned no links of its own. When you are deciding whether a specific page can compete, the page-level metric is the more informative one.

Most often because Moz retrained or recalibrated the model behind DA. Because DA is a prediction of ranking ability rather than a direct count, Moz periodically updates the model and the index behind it, which can move scores across the whole web simultaneously. Your score is relative to every other site Moz measures, so you can also lose points simply because other sites gained links. Check whether competitors moved in the same direction before treating a drop as a problem with your own profile.