What Is Moz Spam Score and What Does It Mean for Your Domain Authority
July 30, 2026
Spam Score is the metric Moz produces that most SEOs either ignore completely or panic about incorrectly. I've had clients forward me screenshots of "high spam scores" convinced their sites were about to be penalized, and I've seen agencies dismiss genuinely problematic link profiles because they didn't understand what the number was telling them. After years of working with it alongside DA and DR, here's an honest breakdown of what Spam Score actually is, when it matters, and when it doesn't.
What Spam Score Actually Measures
Moz's Spam Score is expressed as a percentage from 0 to 100. It represents the percentage of sites with similar link profile features that have been penalized or banned by Google. Moz built it by analyzing thousands of penalized domains, identifying which link profile characteristics correlated most strongly with those penalties, and training a model to flag sites that share those features.
The key word in that definition is "similar." A high Spam Score doesn't mean your site has been penalized or will be penalized. It means your site shares certain measurable characteristics with sites that were penalized. That's a genuinely useful signal — but it's not a direct Google signal, and it's not a verdict.
What Goes Into the Calculation
Moz has published the factors it uses to calculate Spam Score, and they're worth understanding. Sites get flagged when they have combinations of characteristics like: a low number of pages indexed relative to the site's age, a large proportion of followed links pointing to the site from low-quality domains, thin or duplicate content signals, exact-match keyword-heavy domain names, and certain patterns in anchor text distribution.
No single factor produces a high Spam Score on its own. It's the combination that triggers the algorithm. A new site with few indexed pages and a handful of low-quality directory links might score higher than expected, not because it's actually spammy, but because those features statistically correlate with problematic sites in Moz's training data. Understanding this distinction saves you from making decisions based on a misread of the metric.
The Threshold That Actually Matters
Moz considers sites with a Spam Score between 1% and 30% to be in normal territory. Scores from 31% to 60% deserve attention but aren't automatically alarming. Above 60%, there's a real pattern worth investigating. In practice, I use these thresholds when evaluating link prospects: below 30%, I don't think about it much. Between 30% and 50%, I look at the site manually before pursuing a link. Above 50%, I need a specific reason to continue.
When checking your own site's Spam Score in the DA checker, I'd apply similar logic. A score of 15% on a legitimate two-year-old site means nothing. A score of 70% on a site that's been actively link building should prompt a backlink audit.
When High Spam Score Actually Hurts You
High Spam Score on your own site matters in two scenarios. First, if it's being driven by a genuinely toxic backlink profile — lots of links from scrapers, PBNs, or irrelevant foreign directories — that underlying link quality problem is what could eventually attract a Google manual review, not the Spam Score number itself. The score is just the indicator; the links are the actual issue.
Second, if you're trying to sell or buy a site, Spam Score becomes a due diligence item. A site with a DA of 40 and a Spam Score of 75% is worth far less than a site with DA 40 and Spam Score 10%, because the former's authority likely came from methods that will eventually be discounted or penalized. I've seen acquisitions fall apart over exactly this kind of profile mismatch.
When High Spam Score Doesn't Matter
Some legitimate, high-traffic sites have surprisingly high Spam Scores because they operate in industries that attract a lot of unwanted inbound links. Adult content sites link to mainstream brands unexpectedly. Scrapers copy content and generate backlinks. Competitors sometimes point spam links at strong competitors in a negative SEO attempt. To see every link pointing at your site, with likely spam flagged, run a free backlink check. If your Spam Score crept up without any change in your link building activity, that's usually what happened.
I've also seen perfectly healthy news and media sites score in the 40-60% range because they publish a lot of thin, short-form content — which is a feature Moz's model associates with spam — even though those short pieces serve a legitimate editorial purpose. In those cases, the Spam Score is a false positive, and the organic traffic data tells the real story.
Spam Score vs DA: How They Interact
Spam Score and DA measure different things and can move in opposite directions. A site can have high DA and high Spam Score simultaneously — this typically happens when a site built its authority through aggressive link acquisition that worked before Moz's model caught up with the pattern. It can also have low DA and low Spam Score, which simply means a clean but under-linked site.
When I'm running a bulk link prospect evaluation, I pair DA with Spam Score as a quick two-filter system. High DA plus low Spam Score is a strong prospect. High DA plus high Spam Score needs manual review. Low DA plus low Spam Score is a clean site worth building a relationship with for future links. Low DA plus high Spam Score gets cut immediately. Running this across a list of prospects in the bulk DR and TF checker alongside DA gets me most of the way through triage quickly.
Common Questions About Spam Score
Does a high Spam Score mean Google has penalized my site? No. Spam Score is a Moz-calculated metric, not a Google signal. It means your site shares characteristics with penalized sites — that's a flag to investigate, not a confirmation of any penalty. Check Google Search Console for manual actions if you're concerned about an actual Google penalty.
Can I lower my Spam Score by building more good links? Yes, indirectly. Adding high-quality referring domains dilutes the proportion of low-quality links in your profile, which can lower the Spam Score over time. But the faster path is removing or disavowing the low-quality links rather than burying them under good ones.
My competitor has a Spam Score of 80% but ranks well. How? Because Spam Score reflects Moz's risk model, not Google's current assessment of the site. Google may not have acted on that profile yet, or the site's content and user signals are strong enough to outweigh the link quality issues. Sites with genuinely toxic profiles tend to get caught eventually, especially during broad core updates.
Should I avoid building links from any site with a Spam Score above 30%? That's too conservative. I'd avoid sites above 50% without manual review, but a site scoring 25-35% isn't automatically a bad link source. Look at the site itself — real content, real traffic, editorial standards. Those signals matter more than the percentage.
How often does Moz update Spam Score? Moz updates its link index regularly, but Spam Score recalculations don't happen on a fixed public schedule. If you've actively cleaned up your backlink profile, allow at least a few months before expecting meaningful movement. Check your DA and Spam Score together periodically to track the trend rather than a single snapshot.