NoFollow attribute is an HTML attribute that can be added to links to tell search engine crawlers not to follow the link or pass any link equity (also known as “link juice”) to the linked page. Essentially, it instructs search engines that the hyperlink should not influence the ranking of the link’s target in the search engine’s index. The NoFollow attribute is used in the <a> tag, and the syntax looks like this: <a href="http://example.com" rel="nofollow">Link Text</a>.

Introduced in 2005 by Google, Yahoo, and Microsoft, the NoFollow attribute was initially created to combat spam and manipulate the PageRank algorithm by discouraging the use of comment spam and untrusted content links. Over time, its usage has evolved to include a variety of scenarios where webmasters wish to link to a page without endorsing it:

  1. User-Generated Content (UGC): Links within comments, forums, and other types of user-generated content are often marked as NoFollow to prevent spam and the manipulation of search engine rankings through user-added links.
  2. Paid Links: When links are created as part of advertisements, sponsorships, or other commercial agreements, they should be tagged with NoFollow to comply with Google’s guidelines on link schemes. This tells search engines that the link was not naturally earned.
  3. Untrusted Content: If a webmaster wishes to link to a source but does not want to vouch for its credibility, the NoFollow attribute can be used to distance their site from the content they are linking to.

In March 2020, Google introduced changes to how it interprets the NoFollow attribute. It became a hint for ranking purposes rather than a directive that Google strictly followed. Along with this change, Google introduced two additional rel attributes to provide more granular instructions:

  • rel="sponsored": Indicates that the link is part of an advertisement, sponsorship, or other compensation agreements.
  • rel="ugc": Specifies that the link is part of user-generated content, such as comments and forum posts.

Despite these changes, the fundamental purpose of NoFollow remains the same: to allow webmasters to link to content without passing along ranking credit in search engines. Using the NoFollow attribute appropriately helps maintain the integrity of the web and ensures compliance with search engine guidelines, particularly in managing paid links and user-generated content.