This pairing comes up because both tools are known for a headline authority metric: Domain Rating at Ahrefs, Domain Authority at Moz. That framing is a distraction. The metrics are the visible tip of the actual product, which is a link crawler, and the crawler is what you are choosing between.
What you are really comparing
Both companies run their own web crawler, build their own link graph, and publish a score derived from it. Everything downstream, the authority number, the referring domain counts, the gap reports, is an output of that crawl. So the honest question is not which number is better calculated. It is whose index better reflects the part of the web you work in.
That is testable in five minutes. Take a site whose backlinks you can verify by other means, check it in both, and see which one is closer to what you know. It is a small sample and it is still more informative than either vendor’s published index-size claim.
DR and DA, briefly
Both are scores on a compressed scale where the top is crowded and each step near the top is far harder than a step near the bottom. Both are relative rather than absolute: they tell you roughly where a site sits against others in the same index, and nothing about what Google thinks.
Three rules make them safe to use.
Compare within one tool only. A DR and a DA are not convertible and a difference between them is meaningless.
Watch the trend, not the value. A score that has climbed over six months is telling you something. A score of 34 is telling you almost nothing on its own.
Never buy on the metric. Paying for a link because of the seller’s score is the purest form of optimising the proxy instead of the thing, and it is a well-worn route to a link profile that scores well and does nothing.
Where the tools genuinely differ
Depth against approachability. Ahrefs assumes you know what you want and hands you a dense dataset quickly. Moz is easier to walk into, easier to explain to somebody who is not an SEO, and shallower once you push on it. Neither of those is a flaw; they are different products for different users.
Vocabulary. Domain Authority has escaped into general business language in a way Domain Rating has not. If the people you report to already say DA, that has real practical value even though the metric itself is no better.
Everything beyond links. Both bundle keyword research, rank tracking and a site crawl. Both are adequate. If those are the features deciding your choice, this is the wrong comparison and the three-way suite comparison is the right one.
What the authority score cannot tell you
A high score does not mean your pages are in Google’s index, and this catches people out more often than it should. Authority is computed from links; indexing is a decision Google makes per URL, for reasons that have little to do with your domain-level score.
I have looked at plenty of sites with a respectable score and a meaningful share of pages sitting at crawled, currently not indexed. The diagnosis for that is why pages do not show on Google, and it starts in Search Console rather than in either of these tools. If you want the state of every URL at once rather than one at a time, that is what the bulk URL inspection tool is for, and the paid version of the work is indexing.
Nor does either score tell you whether an answer engine will cite you. Being quoted by an AI surface turns on being fetchable and being specific, not on a link-derived number, which is covered in AI search visibility.
Picking one
If links are the centre of your work, Ahrefs, because the index is the product and you will be in it daily.
If links are one input among several, and legibility matters, Moz, particularly where reports go to people who will not be trained on the tool.
If you are undecided, run the five-minute test above on a site you know well and let your own web decide it. That is a better basis than either the metrics or the marketing.
Then stay put long enough to build a history worth having. If the shortlist is still open on price, Ubersuggest vs Ahrefs is the budget question, and if what you actually want is competitor intelligence, Ahrefs vs SpyFu vs Semrush covers that angle.
Quick answers
Is Domain Rating better than Domain Authority?
Neither is better, because neither is a Google metric and neither predicts anything on its own. They are two vendors scoring the same idea, link-based strength, on their own crawls with their own maths, and a site can score noticeably differently in each. What matters is that you compare within one tool and never across them. A site with a higher score in one tool than another has told you about the tools, not about itself.
Does Google use Domain Authority?
No. It is a third-party score, invented by a vendor, calculated from a vendor's crawl. Google has said clearly enough that it has no site-wide authority score of this kind that people can point at, and in any case Google could not use a number computed from someone else's index. The metric is useful as a rough comparative shorthand between sites inside one tool and as nothing else.
Which tool has more backlink data?
Link index size is a claim each vendor makes about itself, and the numbers are not comparable because vendors count differently and refresh differently. What you can do is test on a site you know: check a domain whose links you can verify independently and see which index reflects reality better for your corner of the web. That is a more useful five minutes than any published index-size figure.
Should I chase a higher DR or DA score?
Chase the thing the score is a proxy for, which is relevant sites referring to you, and let the number follow. Optimising for the score directly is how people end up buying links from high-scoring sites with no relevance, which moves the metric and not the rankings. The number is a thermometer. Nobody gets better by heating the thermometer.
Which is better value if I only need link data?
If link research is genuinely the only thing you need, that is the case where Ahrefs is easiest to justify, because the index is the product rather than a feature of it. Moz becomes the better answer when the link data sits alongside other work and the person using it wants a gentler interface and a vocabulary the rest of the organisation already speaks.