A link attribute telling search engines not to pass link equity, used for sponsored content and user-generated links.
Nofollow is a link attribute (rel="nofollow") that instructs search engines not to follow the link or pass link equity (ranking power) through it. When you add nofollow to a link, you're essentially telling Google and other search engines to ignore that link for ranking purposes, though the link remains clickable for users.
The nofollow attribute was introduced by Google in 2005 as a way to combat comment spam and paid link manipulation. By default, all links pass what's called "link juice" or link equity from one page to another, which can influence search rankings. Nofollow breaks this chain, making it a crucial tool for managing how link equity flows through your site and maintaining compliance with search engine guidelines.
Why It Matters for AI SEO
AI-powered search systems like Google's RankBrain and newer algorithms are increasingly sophisticated at detecting manipulative link patterns. The nofollow attribute helps maintain trust signals that these AI systems rely on when evaluating site quality. When AI crawlers encounter proper nofollow usage on sponsored content, user-generated content, or untrusted links, it signals that the site owner follows best practices. Modern AI SEO tools now automatically flag links that should be nofollowed, making compliance easier. However, the landscape has evolved beyond simple nofollow—Google introduced rel="sponsored" for paid links and rel="ugc" for user-generated content in 2019, giving SEOs more precise ways to categorize links that AI systems can better understand.
How It Works
To implement nofollow, add rel="nofollow" to any link tag: Link text. You should use nofollow for sponsored content, affiliate links, links to untrusted sites, and user-generated content like comments or forum posts where you can't vouch for the destination quality.
Tools like Ahrefs, Screaming Frog, and Moz Pro can audit your site's nofollow usage, showing you which links pass equity and which don't. Many SEOs use nofollow strategically for internal link sculpting, though Google has stated that nofollow links may still be considered as "hints" rather than absolute directives. For maximum clarity, use the more specific rel="sponsored" for paid links and rel="ugc" for user-generated content.
Common Mistakes
The biggest misconception is that nofollow completely removes all SEO value from a link. While nofollowed links don't pass traditional link equity, they can still drive traffic, brand awareness, and may provide some indirect ranking benefits. Another common mistake is over-using nofollow on internal links—this can prevent search engines from properly understanding your site structure and may waste crawl budget. Finally, many sites fail to nofollow affiliate links or sponsored content, which can trigger manual penalties if Google detects undisclosed paid link schemes.