Moz Spam Score explained: what it means and how to check it
Updated
The short answer
Moz Spam Score is the percentage of websites with features similar to the one you're checking that Moz found to be penalized or banned by Google. 1 to 30% is low, 31 to 60% is medium and 61 to 100% is high. A high score doesn't prove a site is spammy; it's a signal to look closer at its links and content.
Key facts
- Scale: 1 to 100%. Lower is better.
- Based on 27 features Moz's model found common among penalized sites.
- Low 1 to 30%, medium 31 to 60%, high 61 to 100%.
- Moz updates Spam Score quarterly.
- Older reports used a 0 to 17 flag count instead of a percentage.
What Spam Score actually measures
Spam Score is a correlation, not a verdict. Moz fed its machine learning model millions of sites that Google had penalized or banned, and the model found 27 features those sites tend to share. When you check a domain, Spam Score tells you what percentage of sites with the same mix of features ended up penalized.
So a Spam Score of 45% means: among sites that look like this one on those 27 signals, 45% were penalized. It doesn't mean the site is 45% spam, and it says nothing about the sites linking to it.
You can check it for any domain with our domain authority checker, which shows Spam Score right beside Moz DA and Page Authority.
Spam Score ranges
Moz groups the percentage into three bands, and our report uses the same ones:
| Spam Score | Rating | What to do |
|---|---|---|
| 1% to 30% | Low | Normal for most real sites. No action needed. |
| 31% to 60% | Medium | Take a look at the site's content, links and relevance before trusting it. |
| 61% to 100% | High | Investigate carefully. Avoid links from it unless you've checked it by hand. |
If you see a score shown as a number out of 17, that's the older version of Spam Score, which counted how many of 17 spam flags a site triggered. Roughly, 0 to 4 flags is low, 5 to 7 medium and 8 or more high.
The kind of signals behind it
Moz publishes the 27 signals. Most are innocent on their own; together they paint a picture. A few examples from the list:
- Very few pages found on the domain.
- A top level domain often used by spam sites.
- A long domain name or one containing numbers.
- No phone number, email address or link to a LinkedIn page.
- Missing common site features such as analytics or tag manager scripts.
- Low authority metrics compared with the site's link counts.
This explains why some perfectly honest small sites get a medium score. A two page local site with a numbered domain name can trip several signals without doing anything wrong.
How to use Spam Score when vetting sites
Spam Score shines when you combine it with authority metrics. On its own, it creates false alarms. Together with DA and Trust Flow, it quickly exposes sites whose authority was built with link schemes.
| Pattern | Likely meaning |
|---|---|
| High DA, low Spam Score, healthy Trust Flow | A genuinely strong site |
| High DA, high Spam Score | Authority likely inflated by manipulated links |
| Low DA, medium Spam Score, tiny site | Often just a small site tripping signals |
| High DA, Trust Flow far below Citation Flow | Lots of links, few trusted ones; check carefully |
When you're checking a list of guest post or link prospects, run them through the bulk domain authority checker and sort by Spam Score first. Remove the high ones, then rank the rest by DA.
How to lower your own Spam Score
If your own site shows a medium or high score, don't panic. Moz is clear that a score based on correlation doesn't mean you've been penalized. But it's worth fixing anything that genuinely looks thin or untrustworthy:
- Add real contact details: an email address, phone number and business address where relevant.
- Build out thin sections so the site has substantial, useful pages.
- Link to your genuine social and company profiles.
- Earn a few links from real, relevant sites to balance your link profile.
- Review links you've bought or exchanged and remove the ones you'd be embarrassed to explain.
Spam Score updates quarterly and only changes when Moz's crawler sees changes to those signals, so improvements take time to show. For the broader picture of building trust, see how to increase domain authority.
Spam Score when buying or accepting guest posts
This is where Spam Score earns its keep. Link sellers know buyers filter by DA, so a lot of sites on seller lists have their authority propped up by link networks. Those sites tend to share exactly the features Moz's model flags: thin pages, no real contact details, unrelated outbound links on every post.
Our rule of thumb for any site you're about to pay or write for: under 10% is comfortable, 10 to 30% is fine if the content looks real, and anything above 30% needs you to open the site and read a few posts before going further. Check that the site links out to sensible places, that its articles have real authors, and that it ranks for at least some searches related to its topic.
Spam Score vs “toxic score” in other tools
Other SEO tools have their own risk metrics with names like toxicity score. They're built on different data and different rules, so a site can be low risk in one and flagged in another. None of them is something Google uses. Treat every one of these scores the same way: a reason to look, not a reason to act on autopilot.
Should you disavow links from high Spam Score sites?
Usually not, at least not on Spam Score alone. Google ignores most low quality links automatically, and Moz itself advises checking a site's content and relevance before disregarding or disavowing anything. Disavowing is for clear link schemes you were part of, or a manual action, not for every link with a high score.
A better use of your time is to look at which of your linking domains score high, open a few of them, and decide case by case. Pair that with Trust Flow and Citation Flow for a much clearer read on link quality.
Common questions
What is a good Spam Score?
1% to 30% is low and considered good. Most real, established websites sit in this range.
Is a Spam Score of 1% possible?
Yes. 1% is the lowest Spam Score Moz shows and is common for well established sites with real contact details and strong links.
Does Spam Score affect Google rankings?
No. Spam Score is a Moz metric and Google doesn't use it. It's a warning signal for people evaluating a site.
Why does my Spam Score show 3/17?
That's the older Spam Score format, which counts how many of 17 spam flags the site triggered. Up to 4 flags is generally considered low risk.
How often does Spam Score update?
Moz updates Spam Score quarterly, but a site's score only changes when Moz detects changes in the signals it uses.