Methodology
What each metric means, how we read the data, and how we turn it into a recommendation. If a verdict surprises you, this page shows how we got there.
1. What we measure
Every analysis shows the following metrics for the site’s root domain, together with the date they were measured.
| Metric | Source | What it is |
|---|---|---|
| Domain Authority | Moz | Moz’s 1–100 prediction of how well a domain can rank, built mainly from link data. |
| Domain Rating | Ahrefs | Ahrefs’ 0–100 score for the strength of a backlink profile relative to other sites in its index. |
| Spam Score | Moz | The share of sites with similar features that Moz found penalized or banned by Google. |
| Referring domains | Moz | How many separate domains link to the site, in Moz’s index. |
| Organic traffic | Semrush estimate | Semrush’s estimate of monthly visits from unpaid search, modelled from keyword rankings. |
| Organic keywords | Semrush estimate | How many keywords Semrush sees the domain ranking for. |
| Domain age | Domain registry | The domain’s registration date, from its registry record. |
| Homepage backlinks | Semrush | Backlinks Semrush counts to the exact homepage URL. |
A metric appears on this site only when we can say what it measures.
2. How missing data is shown
- N/A means the value isn’t available. We never substitute 0, an estimate, or a value from another provider.
- “1 (Confirm Manually)” means Moz has no record of the domain, so the 1 is a placeholder, not a measurement.
- When Moz has no Spam Score for a site, we show N/A.
- “not published” means the domain’s registry doesn’t publish a registration date.
3. How we read the data: signals
Each analysis applies the same rules to the measured data. A signal always shows the values it used, so you can disagree with the rule and still use the evidence. The numeric thresholds are our editorial judgment, except the Spam Score bands, which are Moz’s own.
| Signal | Rule | Basis |
|---|---|---|
| Data coverage | Shown only when some of the 8 core metrics are missing; 3 or more missing is flagged as thin data. | Editorial rule. Missing values are shown as N/A, never as 0. |
| Moz record | Flagged when Moz has no record of the domain (DA shown as "1 (Confirm Manually)") or its data is unavailable. | Moz has no record of domains outside its index; a DA of 1 shown for them is a placeholder, not a measurement. |
| Authority estimates | Compares Moz DA with Ahrefs DR. A gap of 25 points or more is flagged. | Editorial rule. Two link indexes disagreeing that much means one of them sees a very different link profile. |
| Spam Score | 31–60% (medium) is flagged as caution and 61% and above (high) as risk. A low score (up to 30%) gets no signal; the meter shows it. | Moz's own low / medium / high bands. The score is the share of similar sites Moz found penalized or banned by Google. |
| Search visibility | Flagged when Semrush returns no traffic figure, zero, or no answer. Healthy traffic gets no signal; the traffic tile shows it. | Editorial rule. Traffic estimates are the clearest public sign that Google sends visitors to a site. |
| Authority without traffic | Flagged when DA or DR is 40+ but estimated organic traffic is under 500 or missing. | Editorial rule. Strong link metrics with little search traffic is a common pattern on sites that exist mainly to sell links. |
| Domain registration | Reports the domain’s registration date. Never scored as good or bad on its own. | A registration date does not show who ran the site since, or whether an expired domain was repurposed. |
4. What a human review adds
Numbers cannot tell you what a site is about or who reads it. For every analysis we also review the site itself:
- Niche and audience, from the site’s own content, not from its name.
- Relevance: which kinds of businesses and campaigns a link there could plausibly help.
- Link types: whether a guest post, link insertion or shared link would fit. We mark a placement as offered only when we have confirmed it, otherwise “not confirmed”.
- Risks: patterns that make a link more likely to be ignored or treated as spam, such as sponsored sections full of unrelated outbound links.
5. Verdicts
Every analysis ends with one of five verdicts. It is a recommendation, not a measurement, and the analysis states the reason for it.
| Verdict | Meaning |
|---|---|
| Worth considering | The data supports a link here for relevant campaigns, after the standard checks. |
| Situational | Useful only for specific niches, link types or goals, which the analysis spells out. |
| Proceed with caution | Warning signs need checking by hand before any money changes hands. |
| Avoid | The evidence points against buying a link here. |
| Not a link-buying target | No placement can be bought here: any link has to be earned editorially, or is user-generated. |
We do not give sites star ratings or a single quality score. A score would suggest more precision than third-party estimates can support.
6. Where Google stands
Google has said it does not use Moz’s Domain Authority in crawling, indexing or ranking, and Ahrefs says there is no evidence search engines use Domain Rating. We use both as rough, comparable estimates of link strength, never as proof. Google’s spam policies treat links bought to pass ranking credit as link spam unless they are qualified withrel="sponsored" or rel="nofollow". Our policy guide covers what that means for anyone buying links.
7. Limitations
- Each provider sees only its own index, so DA, DR and traffic estimates can disagree sharply for the same site.
- Metrics describe the root domain. A new guest post on that domain starts with none of those links pointing at it.
- Measurements age. Check the measurement date, and re-check the live numbers before you buy.
- Traffic figures are modelled from keyword rankings. They are not the site’s analytics.
8. Updates
We re-measure sites and update analyses over time. Each page shows the measurement date and, separately, when the analysis was last edited. Questions or corrections about an analysis: see our contact page and editorial policy.
Methodology questions
Why do some metrics show N/A?
N/A means the value was not available when the site was measured. We never replace a missing value with zero, an estimate or a figure from another provider, because that would present a guess as a measurement.
Why don’t you give websites an overall score?
The underlying metrics are third-party estimates that often disagree with each other. A single score would suggest a precision they cannot support, so we show the evidence, the signals and a written verdict instead.
What does “1 (Confirm Manually)” mean next to Domain Authority?
Moz has no record of the domain, so the DA of 1 is a placeholder rather than a measurement. Check the domain in Moz directly and rely on the other metrics in the meantime.