Spam Score is a metric from the company Moz. According to Moz, it shows what percentage of sites with features similar to the one being researched Moz has found to be penalised or banned by Google. It is not a Google figure: Moz calculates it with its own model and its own index.
Spam Score is a Moz metric, not a Google signal: what it measures according to Moz, what it is based on and why it cannot decide alone which links go.
What Spam Score means
Moz introduced Spam Score on 30 March 2015. At the time it was made up of 17 warning flags. The underlying data covered about 500,000 subdomains that Moz collected in November 2014, after Google's Penguin 3.0 update. According to Moz's help pages, the current version is based on a machine learning model that identified 27 common features among millions of banned or penalised sites in Moz's data.
Moz groups the result into three bands: - Low: 1 % to 30 %. - Medium: 31 % to 60 %. - High: 61 % to 100 %.
A score shown as "--" means Moz has not evaluated that site yet. It is not the same as 0 %.
Spam Score appears in Link Explorer, in the Links section of Moz Pro campaigns and through the Moz Links API. Moz also calculates Domain Authority, another proprietary metric that has its own entry in this glossary. The Moz tool itself is covered on zds.es on the page about Moz and Domain Authority.
How Moz groups Spam Score.
Low1 % to 30 %
Medium31 % to 60 %
High61 % to 100 %
low or mediumaccording to Moz, not a concern if there have been no penalties
highdoes not mean spam, only that it is worth investigating
--not evaluated yet, not the same as 0 %
Spam Scorean estimate by Moz
Manual actions report in Search ConsoleGoogle's source
A Moz figure, not a Google verdict.
How it works
According to Moz, Spam Score depends only on the site itself, its features, setup and content, and not on the links it receives. The 27 signals Moz lists include, for example: - A low number of pages found by Moz's crawler. - A top-level domain common among spam sites, or numerals or several hyphens in the domain name. - No Google Tag Manager, no phone number, no email address or no link to LinkedIn. - Not defaulting to HTTPS, using the meta keywords tag or having very short or very long titles. - Anchor text in outbound links with words from typical spam topics such as pharmaceuticals, adult content or gaming.
Moz makes clear that the numbering says nothing about the weight of each signal and that it does not show which of the 27 a particular site triggers. The score is updated quarterly and only changes if Moz's crawler detects changes in those signals. Moz does not offer a history.
Alongside the site's own Spam Score, Link Explorer shows what share of linking domains falls into each band. That breakdown is what Moz recommends using to review inbound links.
Why it matters
Spam Score rests on correlation, not causation, and Moz says so explicitly. A high score does not mean the site is spam, only that it is worth investigating. For that reason, according to Moz, the answer is not necessarily to change those features on your own site, and if there have been no penalties, a low or medium score should not be a concern.
What Google does is something else. Google's spam policies define link spam, such as buying or selling links for ranking purposes. Google detects violations through automated systems and, where needed, human review, which can result in a manual action. If a site has a manual action, it shows up in the Manual actions report in Search Console. That report is Google's source; Spam Score is an estimate by Moz.
Best practices
Use Spam Score as a filter to decide which linking domains to review by hand, which is the use Moz proposes.
Check a domain's content and its topical relevance to your site before discarding or disavowing a link.
Look at the Manual actions report in Search Console to see whether Google has taken any action.
Compare doubtful links against Google's spam policies, not just against Moz's score.
Always cite Spam Score as a Moz metric with the date it was checked, because it changes every quarter.
Common mistakes
Presenting Spam Score as a Google figure or factor.
Disavowing links only because the domain has a high Spam Score: Moz recommends checking content and relevance first.
Trying to lower your own Spam Score by disavowing links, when according to Moz it does not depend on inbound links.
Adding Google Tag Manager, a phone number or a LinkedIn link to improve the score: these are correlations, not causes.
Reading "--" as 0 %.
Manuel Riveiro RodriguezCEO & Digital Strategist
A technical audit covers this and everything else in one pass.
Spam Score does not come from Google: Moz calculates it with its own model, from the correlation between certain features and sites Moz found to be penalised. Google detects spam with its own systems and reviewers and reports manual actions in the relevant report in Search Console.
What is a good Spam Score?
Moz treats 1 % to 30 % as low, 31 % to 60 % as medium and 61 % to 100 % as high. According to Moz, a low or medium score need not be a concern if the site has not been penalised, and a high score is a reason to investigate, not proof of spam.
Does Spam Score depend on my backlinks?
No, according to Moz. A site's Spam Score is based only on its own features, setup and content. That is why Moz says disavowing links is not the best way to improve it.
Should I disavow links from domains with a high Spam Score?
Not automatically. Moz recommends using the score as the starting point for a review and checking the domain's content and relevance before discarding or disavowing a link.
How often is Spam Score updated?
Quarterly, according to Moz. A site's score only changes if Moz's crawler detects changes in the 27 signals, and Moz does not show how it has developed over time.
