Definition
Spam Score is an SEO metric developed by Moz that assesses the likelihood of a website being penalized or devalued by search engines, particularly Google. It is based on a series of predictive factors, or “spam flags,” that are commonly associated with low-quality or manipulative websites. Each flag a domain triggers contributes to its overall Spam Score, which ranges from 0% (low risk) to 100% (high risk). The more spam flags a domain triggers, the higher the score—and potentially, the higher the risk of search engine penalties.
Spam Score can help SEO professionals identify risky backlink profiles, audit their own domains for vulnerabilities, and avoid questionable link-building partnerships.
Is It Still Relevant?
Yes, Spam Score remains relevant in modern SEO, especially in the context of link building, competitive analysis, and domain auditing. While Moz’s Spam Score is not a direct Google ranking factor, it correlates closely with many signals that search engines use to evaluate site quality and trustworthiness.
Google’s algorithms, notably its Helpful Content Update and their evolving stance on link schemes and low-quality content in core updates, underscore the importance of maintaining a site profile that demonstrates authority, trustworthiness, and authenticity. As such, Spam Score continues to serve as a valuable proxy for risk assessment when evaluating external links and potential SEO partnerships.
Moreover, with increased scrutiny on AI-generated content, short-lived spam tactics, and expired domains repurposed for manipulation, tools like Spam Score help safeguard your site against algorithmic penalties by highlighting red-flag domains and toxic backlinks.
Real-world Context
Here are a few practical applications of Spam Score in digital marketing and SEO campaigns:
- Backlink Audits: Agencies and SEO professionals use Spam Score to evaluate the quality of inbound links. If a large number of referring domains have a high Spam Score, it may signal the need for a link disavow or outreach to remove questionable links.
- Outreach Campaigns: During link-building efforts, marketers analyze the Spam Score of potential websites before initiating guest post requests or partnerships. A domain with a high Spam Score may be avoided to reduce the chance of acquiring toxic backlinks.
- Competitive Analysis: SEOs use Spam Score data to dissect competitors’ backlink profiles, identifying whether they’re benefiting from risky tactics or playing within Google’s guidelines. This informs both offensive and defensive link strategies.
- Expired Domain Evaluation: Investors and site flippers consult Spam Score when purchasing expired domains to ensure they’re not inheriting a toxic link profile that could hinder future SEO performance.
Background
Spam Score was introduced by Moz as part of its suite of SEO metrics in early 2015. The tool emerged in response to the growing need for a risk assessment metric that would go beyond simple backlink counts or domain authority. It was created by analyzing over 17,000 banned or penalized domains to identify common features or patterns that could signify untrustworthy sites.
The original version of Spam Score used 17 flags—such as low link diversity or high number of external links—to identify these patterns. Since then, Moz has continued to refine its algorithm to ensure accuracy and relevance amid evolving search engine technology and SEO practices.
Although Spam Score is proprietary to Moz and not used by Google, it has become an industry-standard tool, referenced frequently alongside other metrics like Domain Authority (DA) and Trust Flow.
What to Focus on Today
As the SEO landscape becomes more sophisticated, here’s how marketers and content strategists can effectively use Spam Score in today’s environment:
- Use spam score as a filtering tool: When conducting backlink audits or building outreach lists, use Spam Score to quickly isolate domains that warrant deeper scrutiny. Avoid making decisions based solely on the score—context matters.
- Investigate flagged sites: If a domain has a high Spam Score, check its content, link profile, and domain history using tools like Wayback Machine, Ahrefs, or SEMrush. Determine whether the spam signals are due to expired use, scraper content, or unnatural link patterns.
- Combine with manual vetting: Use Spam Score in conjunction with manual checks—content quality, readability, site structure, and user experience all play a role in gauging site trustworthiness.
- Prioritize backlink hygiene: Monitor your backlink profile regularly using tools like Google Search Console, Moz Link Explorer, or Ahrefs. Watch for inbound links from low-quality or high-spam-score domains and take necessary actions such as link disavowals.
- Stay updated on Google’s guidelines: Be proactive in understanding Google’s webmaster policies and core update themes. This ensures that your use of metrics like Spam Score aligns with real-world algorithmic changes.
Remember, Spam Score is a directional indicator—not a definitive verdict. With thoughtful interpretation and integration into your broader SEO strategies, it becomes a vital part of your risk assessment toolkit.