Nofollow
Nofollow is a link attribute that tells search engines not to pass ranking credit through that link. You add rel="nofollow" to a link when you do not want to endorse the destination or do not want to vouch for it with your own site's authority.
By default, every link on your site is an endorsement. When you link out to another page, you pass a little of your own authority to it, and that flow of authority is part of how Google decides what ranks. The nofollow attribute is how you say "I am linking to this, but please do not treat it as my personal vote of confidence." You add rel="nofollow" to the anchor tag, and search engines generally stop passing ranking credit through that specific link. It is a way to reference something, or to be forced to link to something, without staking your own site's reputation on the destination.
Google introduced nofollow back in 2005, and the reason was simple: comment spam was out of control. Spammers were dropping links into every blog comment box on the web to siphon authority from sites they had no business benefiting from. Nofollow gave site owners a way to neutralize those links without deleting every comment. The attribute stuck around long after the original problem cooled off, and its use widened to cover any situation where you link out but do not want to vouch for where the link goes.
When to use nofollow
- User-generated content you do not control, like blog comments, forum posts, and profile links.
- Paid or sponsored links, where passing ranking credit would directly violate Google's guidelines.
- Links you are required to include but cannot personally vouch for, including many affiliate links.
- Untrusted destinations you need to reference for context but do not want to endorse with your authority.
Nofollow is a signal, not a wall. Google has treated it as a hint rather than an absolute command since 2020.
Example
You write a product review and link to the item through an affiliate program that pays you a commission. Because that link is commercial and you are being compensated for it, you tag it rel="sponsored", or at minimum nofollow. You still send your readers to the product, you still earn your commission, and you stay clean with Google's rules about paid links, instead of risking a penalty for trying to pass authority you were essentially paid to hand over. Everybody wins and nobody gets flagged.
lightbulbPRO TIP
Since 2019 you have finer tools than plain nofollow. Use rel="sponsored" for paid and affiliate links, and rel="ugc" for user-generated content like comments. Plain nofollow still works as a catch-all, but the specific tags tell Google exactly why you are not endorsing the link, which is the cleaner signal to send.
A hint, not a command
Google now treats nofollow as a hint for ranking purposes and may still crawl the link for discovery. It is no longer the absolute, hard block it was in the early years.
targetThe mistake people make
Some site owners nofollow their own internal links to "sculpt" where authority flows inside the site. Stop doing this. That tactic has not worked the way people imagine for well over a decade, and all it does now is leak the value those internal links should be passing to your own pages. Nofollow is a tool for external links you cannot vouch for, not a tool for shaping your own internal structure. For how links actually build and pass authority, see my link building playbook.
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