Should you really set all comment links to nofollow?

Why does Google emphasize nofollow in comments?

The directive aims to break the PageRank transmission chain to destinations not validated by the website's editor. Comment sections have historically been prime targets for link spam, as they allow anyone to create a backlink to their site without editorial oversight.

By applying nofollow, you signal to Google that you do not endorse these links. The search engine does not follow them for crawling, and most importantly, it does not transfer any SEO juice to the destination. This serves as a dual protection: against pollution of your outgoing link profile and against unnecessary depletion of your crawl budget.

What is the real risk if comments are left as dofollow?

The first danger: you become an unwitting accomplice to a link scheme. If hundreds of comments point to casino sites, dubious pharma, or adult content, Google may interpret your site as participating in a link network. Even if you requested nothing.

The second, less obvious issue: dilution of your link equity. Each outgoing dofollow link consumes a portion of your internal PageRank. Thousands of spammy comments create massive leaks to worthless destinations. Your link budget goes up in smoke to enrich sites that don’t deserve a penny.

Does nofollow really stop comment spam?

No. Nofollow reduces the economic incentive for spammers, but does not stop them entirely. Some continue to post to gain direct referral traffic or to pollute the reputation of the site. Others use bots that do not even check if the links are nofollow before spamming.

The real protection combines multiple layers: nofollow + manual or automated moderation + captcha + anti-spam filters like Akismet. Nofollow alone only removes the SEO carrot; it does not create a physical barrier. It’s an economic signal, not a technical wall.

• Nofollow blocks PageRank transfer but does not prevent Google from crawling the link
• Unmoderated dofollow comments expose your site to penalties for participation in link schemes
• Nofollow decreases the SEO attractiveness of your comments section for spammers, but does not eliminate them completely
• This directive predates the introduction of ugc and sponsored attributes that offer more nuance
• A site with strict moderation can choose to leave some quality comments as dofollow without major risk

Is this recommendation still relevant with the new link attributes?

Google introduced rel="ugc" (User Generated Content) specifically for this use case. It effectively replaces nofollow by being more descriptive: it tells Google, "this link comes from a user, not from me." Google’s historical directive on nofollow for comments dates back to a time when ugc did not exist.

In practice, ugc and nofollow have the same practical effect on PageRank: they block the transfer. But ugc provides additional context to the engine. If you are redoing your implementation today, use ugc instead of nofollow. Google supports both, but ugc is the modern recommendation. [To be confirmed] Google has never clearly confirmed whether ugc offers a ranking advantage over strict nofollow.

Should ALL comment links be set to nofollow/ugc, even the good ones?

Officially, Google says yes. Unofficially, sites with strict human moderation do very well by leaving some quality links as dofollow. If a recognized expert posts a relevant comment with a link to an academic resource or a legitimate tool, why penalize it?

The risk is proportional to the volume and your control capability. A blog receiving 5 comments per month and validating all of them manually can afford selective dofollow. A platform with 10,000 comments a day cannot. Google’s directive is a universal protection covering the worst-case scenario. If you control your environment, you have some leeway.

What are the cases where this rule is consistently ignored without consequence?

Niche forums with a closed community and active moderation often leave links as dofollow. Reddit, Stack Overflow, certain specialized forums: all allow dofollow links in user-generated content. They succeed because their editorial reputation and moderation mechanisms are robust enough.

Google differentiates between an unsupervised WordPress blog and a platform with voting systems, active moderators, and multi-layered anti-spam filters. Context matters. If your site has a good quality history and strong trust signals, a dofollow link in a comment will not trigger a penalty. But why take the risk if ugc does the job without friction?

How to implement nofollow or ugc on existing comments?

The majority of modern CMS platforms (WordPress, Drupal, Joomla) automatically apply rel="nofollow" to links in comments. On WordPress, this has been native for years. Check by inspecting the HTML of an existing comment: the link should have the attribute rel="nofollow" or rel="ugc nofollow".

If your CMS does not do this by default, you have two options. First solution: modify the comment template to add the attribute via a filtering function (add_filter on comment_text for WordPress). Second solution: use a specialized plugin that manages UGC link attributes granularly. Never manually touch the database to modify thousands of comments; you will create inconsistencies.

What mistakes must be avoided in this implementation?

Classic error: applying nofollow to ALL links on the comments page, including internal navigation links or action buttons. Nofollow should target only links inserted by users in the body of the comment, not your site’s system links.

Another trap: forgetting other UGC fields. If you allow users to fill in a URL field in their profile that displays publicly, that link must also be in ugc. The same applies to forum signatures, unverified guest author bios, and publicly displayed custom fields. The UGC scope exceeds just blog comments.

Should you regularly audit outgoing links from comments?

Yes, at least once a quarter if you have significant volume. Extract all your outgoing links from comments using Screaming Frog or an SQL script, and then verify that 100% are correctly set to ugc or nofollow. A theme update or plugin can break this protection without you noticing.

Also check the destination of these links even if they are nofollow. Hundreds of comments pointing to clearly spammy sites send a signal of degraded quality, even without PageRank transfer. Google sees that you are not moderating. Purge spam comments instead of letting them rot with a nofollow. A clean site is better than a graveyard of unindexable spam.

• Check that your CMS automatically applies rel="ugc" or rel="nofollow" to links in comments
• Test across multiple comment types (new, old, different formats) to confirm implementation
• Audit other UGC areas: user profiles, forums, public custom fields
• Exclude internal links and system links from automatic nofollow application
• Implement anti-spam moderation (Akismet, reCAPTCHA, manual validation)
• Regularly delete spam comments instead of leaving them as nofollow
• Document your UGC strategy in internal guidelines to avoid regressions after maintenance