Spam Score
Spam score is a metric developed by Moz that rates the likelihood a website is spam on a scale of 0-100. Higher spam scores indicate links from that site may harm your site, making it useful for link evaluation.
What is Spam Score?
Spam score is a proprietary metric created by Moz that predicts the likelihood that a website or domain engages in spam practices. The score ranges from 0 (least spammy) to 100 (most spammy), with scores typically falling on a spectrum. Moz analyzes over 40 spam signals to calculate this score, including domain age, page authority, link patterns, content quality, and other factors. While not a direct Google ranking factor, spam score is a useful indicator of link quality and website reputation when evaluating potential link sources or analyzing your backlink profile.
Spam score became widely used in the SEO industry as a quick way to evaluate backlink quality and identify potentially harmful links in a link profile. A link from a site with a high spam score (typically above 30-40) is more likely to be useless or potentially harmful than a link from a low spam score site. This makes spam score particularly valuable for link prospecting—checking spam scores of potential link sources before outreach helps avoid low-quality sites that might not pass juice or could damage your domain. Similarly, analyzing your own backlinks and identifying those from high spam score sites helps you decide which links to disavow.
However, spam score has limitations and should be used alongside other link quality metrics. A site with a high spam score might still have some legitimate content, and conversely, a low spam score doesn't guarantee link quality if the link is irrelevant or placed artificially. Moz regularly updates its spam signal calculations as spam tactics evolve, meaning spam scores change over time. The metric works best as one of several factors in assessing link quality rather than as the sole determination of whether to pursue a link or disavow one.
When evaluating links, combine spam score analysis with other metrics like domain authority, page authority, traffic estimates, relevance to your content, and the context of the link. A link from a legitimate site with higher spam score might be more valuable than a link from a low spam score site that's completely irrelevant to your content. Understanding spam score helps make informed decisions about which links to pursue and which to remove, contributing to a healthier overall link profile.
Why It Matters for SEO
Spam score helps identify low-quality and potentially harmful links before you acquire them or after they've been added to your site. Managing spam score in your backlink profile protects your domain from penalties and ensures your links come from legitimate sources.
Examples & Code Snippets
Evaluating Link Sources by Spam Score
# When evaluating a link opportunity:
# Check spam score metrics:
link_source_spam_score = 25 # Moz spam score
page_authority = 42
domain_authority = 38
traffic_estimate = 15000
# Decision framework:
if link_source_spam_score < 20 and domain_authority > 30:
decision = "Good candidate for outreach"
elif link_source_spam_score > 60:
decision = "Avoid - likely low quality"
else:
decision = "Evaluate alongside other metrics"Process for assessing link opportunity spam scores
Use Moz's free spam score checker or your SEO tool's spam score analysis to evaluate potential link sources before outreach. Check spam scores of your top 50 backlinks and consider disavowing any from sites with extremely high spam scores (above 60-70). Monitor your overall link profile spam score over time and investigate any significant increases.
Frequently Asked Questions
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