Domain Authority vs Domain Rating: What's the Difference?

You score a prospect domain: Moz says 72, Ahrefs says 61. Which do you trust?

Both numbers are technically correct — they just measure different things with different data. The gap isn't noise; it tells you something real about each tool's crawl coverage and formula. Understanding why they diverge lets you pick the right metric for the job instead of arguing over which number is "right."

What DA and DR actually measure (and what they don't)

Both metrics answer the same question — how strong is this domain's backlink profile? — but they're not measuring Google PageRank. Google hasn't exposed PageRank publicly since 2016, and it's confirmed it doesn't use DA or DR as ranking signals. These are third-party approximations built from each company's own crawl index.

The 0–100 scale is logarithmic on both: moving from 20 to 30 is easier than 70 to 80. A new domain starts near zero and might sit in the 20s for years before building enough quality links to break 40.

Domain Authority — Moz's metric

Moz introduced DA in 2010. It uses a machine learning model trained on Moz's link index, with linking root domains as the primary input. The model is periodically retrained — which means DA scores can shift across the entire index even if nothing changed on your site. A site you've been tracking for months might drop 5 points with no corresponding drop in real links, just because Moz updated their model.

Update cadence: roughly weekly as Moz's crawler refreshes.

Free access: Moz Link Explorer — 10 free queries/month with an account.

Best for: client reports where stakeholders already know the term, or link prospecting if you're already inside Moz's toolset. DA's wide recognition makes it the default for agency deliverables.

Limitation: when Moz retrains their model, scores shift in ways that aren't tied to actual link changes. If you track DA over time, sudden jumps or drops often reflect index updates, not real changes to your backlink profile.

Domain Rating — Ahrefs' metric

Ahrefs launched DR in 2016. Unlike DA, DR is explicitly relative: it measures your backlink profile strength compared to every other domain in Ahrefs' index. Their crawler processes roughly 8 billion pages per day — one of the largest independent web indexes in existence.

That relative framing matters. DR 70 doesn't mean you have a specific count of backlinks; it means your profile is stronger than most domains Ahrefs has seen. As Ahrefs' index grows and they index more of the web, DR scores can shift even without link changes — though this tends to be smaller and less dramatic than Moz's model retraining effect.

Update cadence: continuous. New links can show up in DR within days.

Free access: Ahrefs backlink checker — DR + top backlinks for any domain, no account required.

Best for: competitor analysis and link prospecting where freshness matters. Because Ahrefs' crawler is continuously active, DR reflects recent link building activity faster than DA does.

Limitation: a domain can have a high DR from a handful of extremely strong links (e.g. one link from Wikipedia) while having a weak profile for a specific niche. DR doesn't weight topical relevance.

Why the scores diverge for the same domain

Three independent sources of divergence:

1. Crawl coverage gaps. Moz and Ahrefs have indexed different parts of the web. A link that exists in Ahrefs' index but not Moz's will boost DR without affecting DA, and vice versa. Neither company publishes their index size comprehensively, so you can't know which links are missing from which tool.

2. Formula differences. DR is relative to Ahrefs' database. DA uses an ML model with undisclosed inputs beyond linking root domains. When Moz retrains, scores can shift 5–10 points globally — a well-documented pattern in the SEO community that has nothing to do with link changes.

3. Update frequency. Ahrefs processes new links continuously; Moz refreshes weekly. A link campaign launched this week will likely show in DR before it shows in DA.

The practical rule: don't compare DA to DR directly. Track one metric over time, not both as a cross-tool comparison. The gap between them isn't diagnostic information — it's an artifact of different systems.

Which metric should you use?

Use DA when:

• Client reports require it — it's the term most stakeholders recognize
• You're already inside Moz's toolset and want consistent data in one place
• You're doing historical tracking against a DA baseline you've built up over years

Use DR when:

• You need a current view of link strength — Ahrefs indexes new links faster
• You're doing competitive analysis inside Ahrefs
• You're evaluating large prospect lists and want a single score that updates regularly

Use neither for:

• Predicting Google rankings — neither metric maps reliably to SERP position
• Auditing brand-new domains — both scores are near-zero for 3–6 months and tell you nothing useful

In practice, most teams pick one tool and stay consistent. Mixing DA and DR in the same analysis adds confusion without adding signal.

Scoring domains at scale via API

Moz's API starts at $99/month. Ahrefs' API is Enterprise-only at $1,499/month. Both require subscriptions before you can touch a single domain programmatically.

If you need authority scores for a prospect list, a content audit, or a data pipeline, RankParse offers a domain-authority endpoint on a pay-per-query model — no subscription, credits never expire.

import os
from rankparse import RankParseClient

with RankParseClient(api_key=os.environ["RANKPARSE_API_KEY"]) as client:
    result = client.domain_authority("stripe.com")

data = result["data"]
print(f"Authority score: {data['authority_score']}")
print(f"Referring domains: {data['referring_domains']}")
print(f"Total backlinks: {data['total_backlinks']}")
print(f"Domain age: {data['registered_at']}")
print(f"Popularity rank: {data['popularity_rank']}")  # Tranco top-100k

The response includes authority_score, referring_domains, total_backlinks, registered_at (RDAP registration date), and popularity_rank from the Tranco top-100k list. Cost: 1 credit per domain.

RankParse's authority score is derived from Common Crawl data — a quarterly web snapshot covering billions of pages. That means it's not continuously updated like Ahrefs DR, but it's also not subject to opaque ML retraining like Moz DA. The score reflects the link graph as seen in the most recent quarterly crawl, which is the same underlying dataset used for all other RankParse endpoints.

For bulk scoring, use the batch endpoint to score up to 50 domains in one call:

import os
from rankparse import RankParseClient

domains = [
    "stripe.com", "vercel.com", "github.com",
    "linear.app", "notion.so", "figma.com"
]

with RankParseClient(api_key=os.environ["RANKPARSE_API_KEY"]) as client:
    result = client.batch(domains)

for item in result["data"]:
    da = item.get("domain_authority", {})
    print(f"{item['domain']}: score={da.get('authority_score')} refs={da.get('referring_domains')}")

Scoring 500 domains costs 500 credits — roughly $0.50 at standard pricing. Sign up for 100 free credits to test against your own prospect list.

What DA and DR can and can't predict

High DA/DR correlates with ranking ability on competitive queries, but the causation runs in only one direction: good links → rankings → high DA/DR. Chasing a DA number is backwards.

DA and DR are lagging indicators of your link profile, not inputs to Google's algorithm. A link from a high-DA site will help your rankings because Google values the link — not because your DA score goes up. If a tactic would build real links that real people would follow, it's worth doing. If you're doing it specifically to raise your DA number, you're optimizing a proxy.

The clearest signal either metric gives: a domain with DR below 20 probably doesn't have enough link equity to rank for competitive terms, regardless of content quality. Use that as a quick filter, not as a target.

Frequently asked questions

Is Domain Authority the same as Domain Rating?

No. Domain Authority is Moz's metric; Domain Rating is Ahrefs'. Both score backlink strength on a 0–100 logarithmic scale, but they're calculated from different crawl databases with different formulas. The same domain will almost always show a different DA and DR.

Which is more accurate, DA or DR?

Neither is "accurate" in an absolute sense — both are approximations. Ahrefs has a larger, more frequently refreshed index, so DR tends to reflect recent link activity faster. DA is more widely cited in client-facing contexts. For bulk API access without a subscription, RankParse's authority score uses Common Crawl data updated each quarter.

Does Google use Domain Authority or Domain Rating?

No. Google has explicitly stated it doesn't use third-party SEO metrics. PageRank is computed internally and has never been public. DA and DR are useful proxies for comparing domains, not signals Google acts on.

How do I check Domain Authority for free?

Moz Link Explorer shows DA for any domain (10 free queries/month). Ahrefs shows DR for any domain via their free backlink checker with no account required.

How do I get domain authority scores via API without a subscription?

Use the RankParse domain-authority endpoint: 1 credit per domain, no subscription, credits never expire. The response includes authority score, referring domain count, total backlinks, domain age, and Tranco popularity rank. Sign up for 100 free credits to start.