Spam Score is a percentage from Moz that estimates how closely a website resembles sites Google has penalized or banned. It is a third-party estimate built from Moz’s own model. This page defines the score, explains how Moz builds it, reads the three threshold bands and shows how to use the number when qualifying link hosts.
What is Moz Spam Score?
Moz Spam Score is the percentage of sites with similar features to the site you are researching that Moz found penalized or banned by Google. A higher percentage means the site shares more features with sites that Google removed or demoted.
The score belongs to Moz and appears in Moz’s Link Explorer and in the Links section of a Moz Pro campaign. It describes a site, never a single link. Moz states that the score rests on correlation with penalization, not causation. The companion guide to Domain Authority explained covers the strength metric that Moz publishes alongside it, and the link metrics guides compare every vendor score.
How is Spam Score calculated?
Moz calculates Spam Score with a machine learning model that identified 27 common features among penalized or banned sites. Each feature is a pattern, such as a low number of pages found, a long domain name or an abnormal ratio of external links to content.
The score reports a correlation, not a cause. Moz states that a high score does not mean the site is necessarily spammy; it signals that the site’s quality and relevance need more investigation.
What do the Spam Score thresholds mean?
Moz groups Spam Score into three bands: low at 1% to 30%, medium at 31% to 60% and high at 61% to 100%. Treat the band as a prompt for review, not a verdict on the site.
| Band | Range | Action in link qualification |
|---|---|---|
| Low | 1% to 30% | Proceed to the standard relevance, indexation and traffic checks |
| Medium | 31% to 60% | Review the site by hand before any request |
| High | 61% to 100% | Reject unless a manual review finds a clear reason for the score |
The Action column is our working heuristic, not a Moz or Google instruction. Moz advises using the score as a guide for investigation, not as a reason to disregard a site.
Is a high Spam Score a Google penalty?
No, a high Spam Score is not a Google penalty. Spam Score is a Moz estimate, while Google reports penalties as manual actions, such as “Unnatural links to your site”, in the Manual Actions report of Search Console.
Moz states that a high score does not make a site spammy by itself. The practical risk runs the other way: hosts that sell placements to every buyer leave a pattern, and Google’s SpamBrain system neutralizes links from sites used for the purpose of passing outgoing links. Credit passed by links that Google classifies as unnatural is lost, even when no penalty exists.
How do you use Spam Score when qualifying links?
Use Spam Score as a first filter on a long host list, then confirm every survivor with relevance, indexation and traffic checks. The score removes obvious problems cheaply and approves nothing by itself, so no host skips the remaining checks.
- Export the host list with the Spam Score column from your metrics tool.
- Remove every host in the high band.
- Open each medium-band host and look for the cause: thin pages, unrelated topics or a link-heavy layout.
- Run the six qualification checks on the hosts that remain.
- Re-check the score of accepted hosts quarterly (our working interval), since a host’s pages and links change.
A profile that already holds links from high-score hosts needs review, not panic. The guide to harmful link signals shows how to sort real problems from scored noise. Disavow remains an advanced feature, and Google’s guidance reserves it for a considerable number of spammy, artificial or low-quality links that have caused or will likely cause a manual action. The disavow service handles that case. Anchor mix is the other half of the picture, and the guide to a natural anchor mix sets the ratios.
Related: the Domain Rating guide.