Comparing Domains: Which Metrics Are Worth Looking At

Most domain comparison reports collapse very different signals into one neat score. That is how a third-party authority metric gets presented to a senior decision-maker as if Google had rated the domain, while a backlink count is treated as proof of future rankings.

DA, DR and AS can be useful, but only for relative comparison inside a defined dataset. They are not Google metrics, they do not measure organic performance directly, and they should not be used alone to justify a domain purchase, a link acquisition budget or a forecast to the board.

What DA, DR and AS actually measure

Domain Authority (DA), Domain Rating (DR) and Authority Score (AS) are proprietary third-party metrics. They are calculated by different companies, using different crawlers, link indexes, models, update schedules and scoring scales.

• DA is associated with Moz and is intended to estimate how likely a domain is to rank in search results compared with other domains.
• DR is associated with Ahrefs and focuses heavily on the strength and distribution of a domain’s backlink profile.
• AS is associated with Semrush and combines link-related signals with other indicators intended to identify the overall quality or authority of a domain.

None of these scores is issued by Google. Google does not publish a current, official “domain authority” number that matches any of them. Google’s Search Central documentation describes ranking systems and links as signals, but it does not endorse DA, DR or AS as ranking scores.

The practical consequence is simple: a DA 50 domain is not automatically equivalent to a DR 50 domain or an AS 50 domain. Even two domains with the same score may have very different link quality, relevance, traffic, technical health and commercial value.

Why the numbers disagree

Every metric is built on a private index. That index is a sample of the web discovered and processed by the vendor, not a complete copy of Google’s index.

Differences arise from several factors:

• Crawler coverage: one provider may have discovered a linking page that another has not.
• Refresh timing: a lost link may disappear from one index within days and remain visible in another for weeks or months.
• Link treatment: vendors differ in how they handle nofollow, sponsored, redirected, canonicalised, deleted and low-value links.
• Scoring model: a metric may reward the authority of linking domains, the number of referring domains, link equity distribution or a combination of these.
• Scale design: a score from 0 to 100 is not necessarily linear. Moving from 20 to 30 does not mean the same increase in capability as moving from 70 to 80.

This is why a disagreement is not automatically evidence that one tool is broken. It often means the tools are looking at different versions of the web and applying different definitions of “strong”.

Metric comparison: who calculates what

Metric	Who calculates it	Primarily based on	Useful for
DA	Moz	Link profile signals and a predictive model of ranking ability within the vendor’s index	Comparing similar domains and prioritising link-building prospects
DR	Ahrefs	Backlink strength, referring domains and how authority is distributed through links	Comparing backlink strength and identifying relative link gaps
AS	Semrush	Link authority, domain signals and quality-oriented calculations in its own database	Screening prospects and adding context to backlink risk reviews
Referring domains	Third-party SEO tools	Number of distinct domains linking to a target	Measuring link-source breadth, provided duplicates and spam are reviewed
Organic traffic estimate	Third-party SEO tools	Keyword rankings, estimated search volume, click-through assumptions and available SERP data	Trend and competitor analysis, not audited traffic reporting
Google Search Console clicks	Google, for a verified property	Observed clicks and impressions for that property in Google Search	Reporting actual Google Search performance for an owned or authorised site

The table shows an important distinction: a third-party score can be useful in a comparison, while a first-party performance metric is more appropriate for reporting what actually happened. If a manager asks, “Did our organic visibility improve?”, Search Console clicks, impressions, average position and conversions are closer to the question than DA, DR or AS.

Which metrics are worth looking at in a domain comparison

1. Relevant referring domains

Count the number of distinct websites linking to the domain, then inspect relevance, placement and editorial context. Ten links from genuinely relevant publications can be more useful than 500 links from unrelated directories, expired-domain networks or automatically generated pages.

For a first review, classify referring domains into three groups: relevant and editorial, possibly useful but weakly evidenced, and clearly manipulative or irrelevant. A domain with 120 referring domains may look stronger than one with 60, but the second can be the better prospect if its links are topical, indexable and earned from real publications.

2. Link quality and concentration

Look at how much of the link profile comes from a small number of sites. If 70% of a domain’s apparent authority is explained by links from five related domains, the profile is less resilient than the headline score suggests.

Review the strongest links manually. Check whether they are followed links, whether the linking page is indexed, whether the page receives any visible traffic, and whether the link is surrounded by relevant editorial content. Do not assume that a high metric score proves that every important link is valuable.

3. Organic visibility and traffic trends

Use estimated organic traffic as a directional signal, not as audited revenue evidence. Compare a minimum of 6 to 12 months where data is available. A domain that has a high authority score but has lost 40% of its estimated visibility over the last year deserves more investigation than a lower-scoring domain with steady growth.

Where you own the property, use Google Search Console and analytics data. Report clicks, impressions, conversions and revenue separately. Third-party estimates are suitable for competitor context; they are not a substitute for first-party measurement.

4. Topic and audience relevance

Relevance is often more actionable than a small difference in authority. A domain that serves the same audience and covers the same subject can be a better link prospect than a famous but unrelated site with a score 20 points higher.

Check the domain’s ranking keywords, top pages, language, country focus and commercial intent. For local SEO, inspect location relevance. For international SEO, inspect whether the domain’s audience and links come from the markets that matter to the business.

5. History, ownership and indexability

Review historical snapshots, major topic changes, ownership changes and periods when the domain was inactive. A previously legitimate domain may have been repurposed for gambling, adult content, foreign-language spam or a private blog network.

Also check whether important pages are indexable, whether the domain has widespread redirects, whether the site returns server errors and whether the strongest links point to pages that still exist. A strong score built on deleted pages has limited current value.

When DA, DR and AS are useful

These scores work best as relative filters. For example, an outreach team may define an initial prospect range of DA 30+, DR 30+ or AS 30+, then manually review every shortlisted domain. The number 30 is a screening threshold, not a universal quality boundary.

They are also useful when comparing similar domains in the same niche and market. If ten competitor sites are assessed with the same tool on the same day, the score can help identify outliers and prioritise research. Consistency matters more than mixing figures from different providers.

Use one provider for a single report, record the date collected, and keep the same metric when comparing progress. A change from DR 42 to DR 48 may indicate a change in the tool’s index or model as well as a change in the site’s links. It should not be described automatically as a 14.3% improvement in Google authority.

When the popular advice is wrong

The popular advice “buy the domain with the highest DA” is wrong when the purchase is intended to support a real business. A high DA domain with an unrelated topical history, toxic links, no relevant audience and declining visibility can be less valuable than a lower-scoring domain with clean history and strong customer relevance.

Another common mistake is treating a score below 20 as worthless. A new or specialist domain may have low authority but still rank for valuable long-tail queries, attract a highly relevant audience or own a brand name that matters commercially. Scores are weak substitutes for business fit.

It is also wrong to report that a score increase proves Google rewarded the site. If DA rises after a campaign, the defensible statement is that the third-party metric increased in that provider’s index. To claim SEO improvement, show changes in impressions, clicks, rankings, qualified leads or revenue and control for seasonality.

A practical evaluation process

1. Define the decision. Decide whether the comparison is for link outreach, competitor research, a domain acquisition, digital PR or a risk review. The right evidence differs by purpose.
2. Collect comparable data. Use the same tool, country setting and date for every domain. Record DA, DR or AS, referring domains, estimated visibility and the number of ranking keywords.
3. Apply a relevance filter. Remove domains with the wrong audience, language, location or topic before ranking them by authority.
4. Inspect the link profile. Review at least the top 20 linking domains and sample another 20 from the wider profile. Look for editorial relevance, indexability, anchor-text patterns and obvious networks.
5. Check trend and history. Prefer at least 6 months of visibility data and investigate sharp changes greater than 30%, especially sudden rises followed by sudden falls.
6. Separate evidence from estimates. Label third-party metrics as estimates and first-party data as observed performance. Do not put both into one blended “SEO score” without explaining the methodology.
7. Set a review budget. A basic manual domain review may take 30 to 60 minutes. For a purchase or migration, allow several hours for history, redirects, backlinks, rankings and legal or brand checks. The review cost is usually small compared with a domain purchase in the $1,000 to $20,000 range.

How to report metrics to a senior audience

Use scores to explain relative position, not to make claims they cannot support. A clear report might say: “Domain A has the highest DR in the selected competitor set, but Domain B has more relevant referring domains and a more stable 12-month visibility trend.” That gives a decision-maker useful context without pretending that DR is a Google verdict.

For executive reporting, pair third-party metrics with business outcomes. A sensible scorecard may include organic clicks, qualified conversions, non-brand visibility, relevant referring domains, technical incidents and revenue. DA, DR or AS can appear in a supporting diagnostic section, with the provider and collection date stated beside the number.

The strongest domain comparison is therefore not the one with the most impressive score. It is the one that combines comparable third-party data with relevance, link quality, historical stability, observed search performance and a clear explanation of uncertainty.

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