Nofollow is an HTML link attribute (rel="nofollow") that instructs search engines not to follow a hyperlink or pass ranking authority to the target page. Created in 2005 to combat comment spam, it remains essential for managing link equity and avoiding search engine penalties. Marketers use it to distinguish between editorially earned links and paid or user-generated content.
What is Nofollow?
The nofollow attribute appears within an anchor tag as rel="nofollow". It signals to search engines that the link should not influence the target's ranking in search results. Google introduced the value in early 2005 alongside Blogger to address spammy blog comments that manipulated PageRank. Originally a strict directive, Google now treats nofollow as a hint rather than a command as of March 1, 2020, meaning they may choose to follow the link or use it for ranking purposes at their discretion.
Why Nofollow matters
- Avoid Google penalties: Marking paid links with nofollow or sponsored attributes prevents the "unnatural outbound links penalty" that occurs when sites show patterns of manipulative linking.
- Maintain natural link profiles: Healthy backlink profiles contain a mix of followed and nofollowed links. For example, 23% of YouTube's links are nofollow, demonstrating that natural profiles include unendorsed links.
- Drive referral traffic: Links from high-authority sites like Wikipedia or news outlets generate targeted visitors even when they carry the nofollow attribute.
- Manage crawl budget: Using nofollow on internal links to low-value pages (like login screens or filtered search results) can help prevent search engines from wasting resources on irrelevant URLs, though robots.txt offers more reliable control.
How Nofollow works
When a search engine encounters a nofollow link, it generally excludes it from ranking calculations. However, implementation varies by engine. Google historically ignored these links for PageRank purposes, but as of March 1, 2020, treats them as hints. Yahoo follows the link but excludes it from ranking, while Bing respects the attribute for ranking calculations. In 2009, Google changed its algorithm to prevent PageRank sculpting; previously, nofollowing some links would concentrate authority on followed links, but the update caused nofollowed links to evaporate PageRank instead.
Types of Nofollow and Related Attributes
While standard nofollow remains valid, Google introduced two specific qualifiers in 2019. Use rel="sponsored" for advertisements and paid placements. Use rel="ugc" for user-generated content like forum posts and comments. You can combine attributes using spaces or commas, such as rel="nofollow sponsored" or rel="nofollow,ugc".
Best practices
- Mark all paid links: Use
rel="sponsored"orrel="nofollow"for advertisements, sponsorships, and compensated placements to comply with Google's guidelines. - Tag user-generated content: Apply
rel="ugc"to links within comments, forum signatures, and guest post submissions that you don't manually review. - Don't sculpt PageRank: Adding nofollow to internal links no longer concentrates authority on other links; it simply causes that authority to evaporate.
- Prefer robots.txt for crawling: To prevent crawling of faceted navigation or filter pages, use disallow directives in robots.txt rather than nofollow, as Google may still follow nofollowed links when treated as hints.
- Combine attributes when needed: For paid links that are also user-generated, use both values:
rel="ugc sponsored".
Common mistakes
Mistake: Adding nofollow to all outbound links to "preserve authority". This eliminates the natural link profile signals Google expects and may appear manipulative. Fix: Only nofollow links that are paid, user-generated, or untrusted.
Mistake: Using nofollow for internal PageRank sculpting. This tactic stopped working in 2009 and now wastes link equity. Fix: Remove nofollow from internal navigation and use site architecture to prioritize important pages.
Mistake: Confusing nofollow with noindex. Nofollow controls link crawling; noindex controls page indexing. Fix: Use noindex meta tags to keep pages out of search results, not nofollow links.
Mistake: Assuming nofollowed backlinks have zero SEO value. Fix: Evidence shows nofollow links can improve rankings, and a SurveyMonkey test demonstrated Google followed a nofollow link and indexed a page within 48 hours.
Examples
Widget badges: A software company provides embeddable badges with links to their site. These should carry rel="nofollow" or rel="sponsored" because they are not editorially placed endorsements.
Wikipedia citations: References in Wikipedia articles use nofollow. While they pass no direct PageRank, they drive significant referral traffic and often lead to followed links from other sites that cite Wikipedia.
Blog comments: WordPress automatically adds rel="nofollow" to comment links by default. This prevents spammers from gaining SEO benefits while allowing legitimate discussion.
Press releases: Links within press releases distributed across wire services should use nofollow, as they are not organic editorial links.
Nofollow vs Noindex
Nofollow operates at the link level, affecting individual hyperlinks. Noindex operates at the page level, preventing the entire page from appearing in search results. A nofollow link on an external site does not prevent that page from being indexed; it merely suggests the search engine not follow that specific link. Conversely, a noindex meta tag on your page prevents indexing regardless of how many followed links point to it.
FAQ
Do nofollow links help with SEO? Yes. While they generally do not pass PageRank directly, studies indicate they correlate with rankings similarly to followed links. They also drive referral traffic and can lead to followed links from other sources.
When should I use sponsored or ugc instead of nofollow?
Use rel="sponsored" for any paid or compensated links. Use rel="ugc" for user-generated content like comments and forum posts. Use rel="nofollow" for untrusted links that are neither paid nor user-generated.
How do I check if a link is nofollow?
Right-click the page and select "View page source," then search for the link HTML. If you see rel="nofollow", the link is nofollowed. Alternatively, use browser extensions to highlight them automatically.
Does Bing treat nofollow differently than Google? Bing updated guidelines in June 2020 to suggest using nofollow or sponsored for paid links. Like Google, Bing excludes nofollowed links from ranking calculations, though they may still crawl the target page.
Can I use nofollow on internal links? You can, but it offers no SEO benefit. Since 2009, internal nofollow causes PageRank to evaporate rather than being redistributed. Use site architecture and robots.txt to manage crawling instead.
