Can nofollow links really help Google spot malicious sites?

Why is Google interested in using nofollow for threat detection?

The nofollow attribute was created to signal to Google that a link should not pass PageRank or influence rankings. Historically, it was mainly used to combat comment spam and paid links.

But Gary Illyes is opening up a new avenue here: using these signals to identify dangerous sites. The idea is simple — if a large number of sites add nofollow to the same target, it may indicate suspicious behavior: forced downloads, malicious redirects, spam stuffing. Nofollow then becomes a collective alert signal.

Google already has robust anti-malware systems (Safe Browsing, phishing detection), but this approach introduces a community dimension. Webmasters, by marking a link as not recommended, contribute — consciously or not — to a distributed vigilance system.

Is this method really new?

Not entirely. Google has always analyzed abnormal link patterns to detect spam networks or manipulation schemes. The nofollow attribute itself was already an indirect indicator: too many nofollows concentrated on a domain could suggest that it was unreliable.

What changes is the explicit use of a defensive rather than punitive approach. Google is no longer just penalizing artificial links — it is considering using nofollow to protect the ecosystem. This aligns with the idea of enhancing the user experience: fewer clicks to dangerous sites result in fewer negative signals raised to the SERPs.

In practical terms? If you consistently apply nofollow to suspicious external links, you are participating — even unconsciously — in a collective curation process. Google can then cross-reference this data with other signals (high bounce rates after clicking, user complaints, suspicious SSL certificates) to refine its filters.

What are the limitations of this approach?

The first difficulty: noise in the data. Not all sites apply nofollow for the same reasons. Some apply it by default to all external links, while others only on sponsored or UGC links. It's challenging for Google to distinguish between a “cautious” nofollow and a “red alert” nofollow.

Moreover, this method relies on a fragile assumption: that webmasters will indeed mark suspicious links. Many sites do not manage their link attributes finely. CMSs add nofollow by default, and editors click without thinking. The signal becomes noisy, even unusable without heavy processing.

Finally, Gary Illyes clarifies that there is “no concrete announcement.” This means this avenue is in the exploratory stage. Google may be testing correlations internally, but no public deployment is planned. In other words: don't bet on this feature for your defensive strategy yet.

• Nofollow becomes a potential signal for detecting malicious sites, beyond its primary function of managing PageRank.
• Google has not officially confirmed anything — it's a line of thought, not an active feature.
• This approach relies on collective curation: webmasters indirectly signal suspicious sites by adding nofollow.
• The limitations are real: many sites use nofollow by default, making the signal difficult to interpret.
• No immediate impact on your SEO practices, but it reinforces the importance of clean link building and monitoring linked domains.

Does this statement change anything in our current practices?

Honestly? Not in the immediate term. Gary Illyes talks about exploration, not deployment. No algorithmic changes are announced, and no official guidelines are published. For now, this statement is more about strategic monitoring than on-the-ground action.

That being said, it confirms an underlying trend: Google is constantly refining the use of link attributes (nofollow, sponsored, ugc) to better understand the web. If nofollow does indeed become a tool for detecting threats, it will further reward sites that maintain their link hygiene — those that don't point to just anything, monitor their backlinks, and regularly clean their exits.

Another point to note: this logic could enhance the importance of the ugc (User Generated Content) attribute. If Google wants to distinguish a “ suspicious ” nofollow from a “ cautious ” nofollow, it will need to cross-reference several signals. Sites that correctly use ugc on comments or forums will facilitate this distinction. The result: better algorithmic treatment of their content.

Can we already observe this behavior in the SERPs?

[To be verified] — no public data confirms that Google is already using nofollow to detect malicious sites. Existing security tools (Safe Browsing, phishing detection) rely on other signals: code analysis, SSL certificates, user complaints, abnormal bounce rates.

What we do observe, however, is that Google increasingly penalizes sites that point massively to suspicious domains. No need for nofollow for that: the algorithm identifies toxic link patterns (PBN networks, link farms, cascading redirects). If nofollow comes into play, it will be a complementary signal — not a replacement.

In practice, it's difficult to isolate the impact of nofollow in these cases. A site that experiences a drastic drop after accumulating dubious backlinks will never know if nofollow played a role — or if it was just Penguin striking. The ambiguity persists, and that's likely intentional: Google keeps its cards close to its chest.

Should we modify our linking strategy accordingly?

No — at least not until an official announcement. Continuing to apply best practices is enough: don't buy links, avoid private networks, diversify anchor texts, regularly audit your backlink profile. Nofollow remains primarily a tool for managing PageRank and signaling sponsored or user-generated content.

What could evolve is the perception of nofollow as a defensive tool. If Google confirms this avenue, it will be necessary to monitor even more finely the domains we link to — even with nofollow. An external link to a site that turns out to be toxic could, in the long run, send a negative signal. But we are far from that. For now, it's informed speculation.

One last point: this statement reminds us that Google is constantly testing new analysis methods. What does not exist today may emerge in six months. Staying vigilant remains essential — and that's precisely why this type of statement deserves to be documented, even if it has no immediate impact.

What should you check on your site right now?

The first step: audit your outgoing links. Use a crawler (Screaming Frog, Sitebulb, OnCrawl) to list all the external links present on your site. Identify those pointing to unknown, suspicious, or low-quality domains. If you find links to sites that force downloads, redirect to spam, or present dubious SSL certificates, add nofollow — or even better, remove them.

Next, ensure that your link attributes are properly configured. Sponsored links should carry the sponsored attribute, comments and forums should use ugc, and external links to sites you do not fully endorse should be nofollow. This fundamental hygiene is not new, but it takes on added significance if Google indeed uses these signals to detect threats.

Finally, monitor your incoming backlinks. A site accumulating links from toxic domains — even with nofollow — can send negative signals. Use Google Search Console, Ahrefs, Majestic, or SEMrush to identify suspicious domains and disavow the most dangerous ones using the Disavow Tool. This precaution remains relevant, regardless of how future algorithm changes unfold.

What mistakes should be avoided when using nofollow?

The first mistake: applying nofollow everywhere by default. Some SEOs, out of excessive caution, apply the attribute to all external links. The result: the signal becomes unusable for Google. If everything is nofollow, nothing is really. You also lose the opportunity to build legitimate link relationships, which remain an important ranking factor.

The second mistake: confusing nofollow and disavow. Nofollow applies to outgoing links you control, while disavow applies to toxic incoming backlinks you do not control. Do not mix the two. If a dubious site links to you, you cannot impose a nofollow on it — you need to go through the Disavow Tool.

The third mistake: ignoring the new attributes sponsored and ugc. Google introduced these to refine the understanding of links. Using them correctly helps the algorithm interpret your site better. A sponsored link marked nofollow instead of sponsored is not critical, but it's less precise. And if Google indeed develops a detection system based on attributes, it's better to start on solid ground.

How to integrate this monitoring into an overall SEO strategy?

This statement fits into a broader trend: Google is constantly refining its signals to better understand the quality of sites. Nofollow is just one indicator among many — SSL certificates, loading speed, Core Web Vitals, user behavior, backlink profile, content freshness. The goal is to maintain an overall coherence.

In practical terms, this means not isolating link management from the rest of your strategy. A site that takes care of its outgoing links but neglects its security (no HTTPS, XSS vulnerabilities) sends contradictory signals. Similarly, a site that accumulates quality backlinks but points to suspicious domains loses credibility. The coherence of all signals strengthens the authority perceived by Google.

Finally, keep in mind that these optimizations can be complex to orchestrate alone — especially on large sites with thousands of pages and links. If you're lacking time or internal resources, it might be wise to consult a specialized SEO agency for a thorough audit and personalized support. These experts have the tools and field experience to quickly identify areas of risk and implement lasting fixes.

• Audit all outgoing links and identify suspicious or low-quality domains.
• Properly apply nofollow, sponsored, and ugc attributes according to the context.
• Regularly monitor incoming backlinks via Google Search Console and third-party tools.
• Use the Disavow Tool to disavow toxic domains pointing to your site.
• Do not apply nofollow everywhere: preserve legitimate outgoing links to maintain healthy linking relationships.
• Cross-reference this monitoring with other signals (security, performance, content) for a coherent SEO strategy.