Dofollow vs. Nofollow Links: What They Tell Search Engines

Where nofollow came from

Google introduced rel="nofollow" in 2005 to help sites fight comment and forum spam — a way to add a link without vouching for where it led. For over a decade, Google's search algorithms treated nofollow as an instruction to ignore the link entirely for ranking purposes.

Sponsored, UGC, and the shift to "hints"

In September 2019, Google added two more specific attributes: rel="sponsored" for paid or compensated links like ads and sponsorships, and rel="ugc" for links inside user-generated content such as comments and forum posts. At the same time, Google changed how all three attributes are treated for ranking and crawling purposes — from absolute directives to "hints" it can weigh alongside everything else, a change that took effect for crawling and indexing in March 2020.

What this means for link building

Paid or contributed placements are generally expected to carry sponsored or nofollow attribution under Google's link-scheme guidance — a paid link passed as a plain, unmarked dofollow link is exactly the pattern Google's spam policies target. In practice, a natural link profile contains a healthy mix of dofollow and nofollow links; an all-dofollow profile built entirely through paid placements is itself a signal worth avoiding, not a goal to chase.