When people check domain spam score, they usually want a yes or no: is this site safe to buy, link from or accept links from? The number does not answer that question. It measures resemblance. A site with a high score shares features with sites that were penalised, which is useful to know, but it says nothing direct about the site’s content, its links or its history with Google.
This post sets out what Moz’s own help page says the metric is, what it leaves out, and how to use it as a first filter before the manual checks that actually decide things.
What Spam Score actually measures
Moz defines it plainly. In its Help Hub, the Spam Score page says the metric “represents the percentage of sites with similar features to the site you’re researching which we’ve found to be penalized or banned by Google.” The model behind it “identified 27 common features among the millions of banned or penalized sites in the data we fed it.”
Read that twice. A score of 40% does not mean the site is 40% spammy. It means that, of the sites Moz has seen with a similar mix of features, around that share were penalised or banned. It is a population statistic applied to one site.
Moz is also clear that the metric is about the site itself, not the sites linking to it. Its FAQ asks whether Spam Score is a calculation of the score of sites linking to you and answers: “No, it’s not.” Link Explorer separately shows a breakdown of the percentage of linking domains that fall into each Spam Score band, which is a different view and worth keeping apart in your head.
The three bands, and what Moz says to do
Moz gives three bands and no pass mark. Nothing on the page says a link is safe below a particular percentage, so treat any “keep it under X%” rule you have seen elsewhere as folklore.
| Band | Range (Moz) | What Moz advises |
|---|---|---|
| Low | 1%–30% | No concern if you have had no penalties |
| Medium | 31%–60% | No concern if you have had no penalties |
| High | 61%–100% | Investigate quality and relevance; don’t auto-disavow |
| “–“ | No score | Moz has “not evaluated the Spam Score of that site yet” |
On a high score, Moz writes that it “doesn’t mean this site is necessarily spammy. It’s a sign that you should do some more investigation into the quality and relevance of this site.” For your own site, it adds that “If you have not had any penalties you shouldn’t be concerned about a Low or Medium score.”
Correlation, not cause: what the number misses
The most important line on Moz’s page is this one: “Since this is based on correlation with penalization rather than causation, the solution isn’t necessarily to change these factors on your site.” Removing a hyphen from your domain will not make you less likely to be penalised. It would only change how much you look like sites that were.
Nor does Moz say Google uses Spam Score, or that a high score causes ranking losses. It is a third-party metric, in the same family as the authority scores compared in our post on Domain Rating vs Domain Authority. Useful, but not Google’s view of anything.
The help page’s FAQ also lists gaps that matter in practice:
- No history. “No, we do not currently have a way to show historical Spam Score.” You cannot see whether a domain scored worse before it dropped.
- No breakdown. “Which of the 27 features your site triggered isn’t currently available.” You see the total, not the reasons.
- No disavow awareness. Moz says “we don’t have a way to identify links you’ve disavowed.”
- Slow updates. The score “updates quarterly”, and a site’s score only changes if Moz’s crawlers detect changes affecting the 27 signals.
Signals that produce false positives
Moz lists the 27 signals and notes that their order “has no bearing on the importance of each signal.” Several describe perfectly ordinary small sites. The first signal says as much: a small page count “is not an inherent problem, but many spam sites have small numbers of pages, hence the correlation.”
| Signal (Moz’s wording) | Why a clean site might trigger it |
|---|---|
| Low number of pages found | A new site or a tight niche site with few posts |
| Browser Icon (“Spam sites rarely use a favicon”) | An owner who never added one |
| Domain name contains numerals | A brand with a number in its name |
| Hyphens in Domain Name | A descriptive, hyphenated name |
| Use of Meta Keywords | An old theme or plugin still printing the tag |
| TLD correlated with spam domains | A legitimate site on a TLD such as .biz |
Other signals on the list, such as “Presence of Poison Words” or “Uses High CPC Anchor Text”, are harder to explain away, which is exactly why a manual look beats arguing with the total.
How to check domain spam score and act on it
You can look up a single domain in Moz’s Link Explorer. For bulk work, Moz says the score is available “via the Moz Links API or by creating a Link Tracking List and exporting the data to CSV”, with export limits tied to your subscription level. Then treat the result as triage:
- Sort, don’t decide. Use the bands to choose which domains to open first. High scores go to the top of the pile, not straight into a disavow file.
- Read the site. Moz’s advice is to “check out a site’s content and its relevance in linking back to you before disregarding or disavowing.” Our guide on how to check backlinks covers the wider review.
- Think before disavowing. Most odd-looking links need no action. Read whether toxic backlinks matter and our notes on disavowing links before you file anything, and negative SEO if a sudden flood worries you.
Expired domains need one extra step. A score built from on-site features reflects the site as Moz last crawled it, and Moz cannot show history. Before trusting it, look at what the domain used to be: the Domain History Checker shows a year-by-year Wayback Machine timeline, past page titles, topic changes, gaps and redirects. Our post on expired domains for SEO covers the rest of the vetting.
The limitation is worth stating plainly. Spam Score cannot tell you whether a site has actually been penalised, which of the 27 signals it tripped, or how its score has moved over time. It describes resemblance from a quarterly crawl. Everything that decides whether a link or a domain is worth having still needs a human to open the site and read it.
Frequently asked questions
Is Spam Score a Google metric?
No. It is Moz’s own metric, based on how closely a site’s features match sites Moz found to be penalised or banned by Google. Moz does not say Google uses it.
What is a good Spam Score?
Moz gives bands rather than a pass mark: 1%–30% is Low, 31%–60% Medium and 61%–100% High. It says you shouldn’t be concerned about a Low or Medium score on your own site if you have had no penalties.
Should I disavow links from high Spam Score sites?
Not automatically. Moz recommends using the score to start an investigation and checking a site’s content and relevance before disregarding or disavowing it.
How often does Spam Score change?
Moz says it updates quarterly, and an individual site’s score only changes when its crawlers detect changes that affect the 27 signals.
The takeaway Spam Score tells you which sites look like penalised ones. Use it to decide what to inspect first, then judge each site on its content and relevance.
