Ahrefs vs Moz

Ahrefs describes Domain Rating as the strength of a site's backlink profile compared with every other site in its database. Its help centre says the calculation starts from unique referring domains. Each linking domain passes on rating, split equally among all the domains it links to. The process repeats, and the result is placed on a 100-point logarithmic scale.

Two consequences follow from Ahrefs' own description. A link from a DR 10 site that links to three domains can move your DR more than one from a DR 80 site linking to a million. And DR ignores nofollow links, spam, traffic and domain age entirely. It is a statement about links and nothing else.

Moz describes Domain Authority as a score that predicts how likely a site is to rank compared with its competitors. A machine-learning model calculates it from dozens of factors, led by linking root domains and their quality, fitted to signals that correlate with rankings. It runs from 1 to 100, and a new site starts at 1.

So an Ahrefs vs Moz comparison of the two scores sets a count beside a forecast. DR answers how strong a link profile is. DA answers how likely the domain is to rank. Moz also retrains the model from time to time: its 2019 rollout of Domain Authority 2.0 changed how every score was calculated.

The gap between a site's DA and its DR is not an error in either tool. The inputs differ, because each vendor runs its own crawler and keeps its own index. The formulas differ, as the section above sets out. And both scales are relative, so a site's number moves when other sites gain links.

Both vendors explain that last point the same way. When a site at the top of the scale gains more links, it cannot go any higher, so everyone below is pushed down. Moz notes that climbing from 20 to 30 is easier than from 70 to 80. Ahrefs says a DR can fall with no links lost.

The crawlers also choose pages differently. Moz says its crawler uses a machine-learning model trained to favour pages like those in its own collection of Google results. Ahrefs says its bot crawls around five million pages a minute. Neither claim tells you which index holds your links, and only a check against your own data can.

In a February 2026 r/bigseo thread, a poster whose site read DA 11 and DR 16 asked which one to care about. The subreddit's moderation bot answers any mention of DA with a stock reply dismissing it as a third-party metric. The human replies said neither, and pointed to Search Console clicks and impressions instead.

Ahrefs says its backlink index takes in fresh data every 15 to 30 minutes, and that a complete refresh of the whole database takes about two months. Pages are revisited anywhere from once to 60 times in that period, depending on their rating. Its help centre lists a 12-hour update frequency for Domain Rating on the project dashboard.

Moz says the index behind Link Explorer is constantly updating, and that newly found links reach Link Explorer in about three days. It aims to recrawl high-quality pages at least every 90 days. Most links in its index come from pages crawled within the last six months, and links do not drop out for age alone.

Domain Authority only moves when Moz finds new links to the site, or when Moz changes the model. Spam Score, the separate risk figure Moz shows beside DA, updates quarterly. Ahrefs lists no equivalent spam figure in the plan table read for this page, and states that DR takes no account of link spam.

For a report that goes out monthly, both cadences are fast enough. For a campaign where you want a new link to register within the week, Ahrefs publishes the shorter path. I would still test both against a link you know went live on a known date before trusting either claim.

Moz's Link Explorer page gives its index as 45.5 trillion links, 8.7 trillion URLs and 1 billion domains. On the same day, the site's own navigation described it as over 44 trillion links in one menu and over 40 trillion in another. None of the three figures carries a date on the page.

Ahrefs' data page counts differently: 35.0 trillion records of external backlink history, 493.9 billion pages in the index, 209.5 million domains after vetting and 28.7 trillion internal backlinks. Its pricing page calls its crawler the world's second most active. One of its help articles says third.

None of these numbers can be set against each other. Moz counts links, URLs and domains. Ahrefs counts backlink history records and domains after vetting, which by its own description is a filtered count. A larger headline in one unit says nothing about how well either index covers the sites you care about.

The test that settles it costs nothing. Export the linking domains Search Console reports for your own site. Then look the site up in each vendor's free tier: Ahrefs Free on a site you can verify, and a free Moz Community account, which allows ten Link Explorer queries a month. Whichever finds more of Google's list covers your corner of the web better.

Ahrefs released a free Domain Rating endpoint on 8 June 2026, according to its API changelog. Since 10 August it needs an API key, which any free Ahrefs account can generate, and requests still consume no API units. A second endpoint added on 31 July returns the top million domains by DR, up to 250,000 rows a request.

Moz's route to Domain Authority in bulk is the Moz API, and Moz's own guide to DA points readers there for larger projects. The free tier gives 50 rows a month at one request every ten seconds. Paid plans run from $20 for 3,000 rows to $500 for 500,000, and Advanced sells 4 million rows for $2,000.

Per thousand lookups, that is $6.67 on the $20 plan, $5.00 on the $75 plan, $2.08 at $250 and $0.50 at $2,000. That assumes one row per domain with no history requested; asking for history, or calling weighted endpoints, uses more. Domain Rating from the free endpoint costs nothing at any of those volumes.

The dates explain some of the advice still in circulation. In a November 2025 r/TechSEO thread, a developer needing 2,000 to 15,000 checks a month for under $100 found Moz's free tier cut to 50 calls a month and asked what else to use. The replies pointed at other vendors' data. The free DR endpoint did not exist yet.

Our own link building directory gives a count rather than an impression. Of the 38 specialists listed there, all read on 16 September 2026, eight band their prices by Ahrefs DR alone and one by Moz DA alone.

Three more mix their measures: one uses DA for guest posts only, one lets the buyer choose a score, and one blends DR with traffic and other signals. Six marketplaces price each publisher individually, and 20 name no score at all. Among the sellers who do name one, DR is the usual currency.

Client reporting can pull the other way. A client who has seen DA in monthly reports for years will ask for it, and swapping in DR changes both the number and what it means. That is a conversation about method, and it goes better before the first report than after it.

Both vendors also control how their score appears in public. Ahrefs requires "Domain Rating by Ahrefs" with a link beside every figure. Moz's API terms require its logo, linked to moz.com, in the same context as the metric. They forbid white-labelling, and forbid calling Domain Authority by any other name.