What is rel=nofollow?
- Using rel=nofollow tells search engine crawlers not to follow a link.
- It indicates that a link is not endorsed by the original author or publisher of the page.
- It is also used when a link is included due to a commercial (paid) relationship.
The above code is basically saying...
- Here is a link to example.com
- If you are a search engine, please do not give credit to this link as I do not endorse it.
"The nofollow keyword indicates that the link is not endorsed by the original author or publisher of the page, or that the link to the referenced document was included primarily because of a commercial relationship between people affiliated with the two pages." 1
Where is it used?
Since rel=nofollow is a link specific directive, it is used within the HTML of a link.
Prior to rel=nofollow you either had to nofollow all the links of a page, or none at all. Now that we have rel=nofollow we can use it link by link by adding it to specific links.
The main reasons for rel=nofollow to exist is to control spam and to notate paid links.
- 2004: Search engines introduce rel=nofollow to control comment spam
- 2005: Recommended by Google for paid links
- 2016: Added to the Google webmaster guidelines
In the end however, most people use it now to reduce the risk of search engine ranking penalties.
When should rel=nofollow be used?
There are four main scenarios when rel=nofollow is recommended.
- Untrusted content
- Paid links
- Crawl prioritization
- Protection from penalization
1. Untrusted content
There are many situations where you might not have control of what people are publishing on your site. Common scenarios are...
- Blog comments
- Forum discussions
- Social widgets
In the above situations, it is wise to make sure that any links are using rel=nofollow. If you are not using no follow on untrusted links, you are basically inviting spam and potentially risking your search engine ranking.
2. Paid links
Google penalizes sites that do not add rel=nofollow to paid links.
If you have the following types of links, you should no follow them...
- Paid link (someone gave you money or services to add a link)
- Affiliate links
- Ads in general
- Links with optimized anchor text in articles or press releases distributed on other sites
Adding rel=nofollow to paid links is even in the Google webmaster guidelines now. Learn more about paid links here.
3. Crawl prioritization
Crawl prioritization means changing the way that search engine crawlers like Googlebot interact with your site.
In some scenarios there is a limit to how many pages search engine crawlers will actively crawl.
An over simplified example of this would be if a website had 100 pages and for some reason 90 of those pages were not important to search engines or ranking (login pages, search result pages, privacy policies or anything else that doesn't really matter as far as ranking).
In this scenario, those ten pages that are important would be the ones that you would want crawled, not the other 90.
By adding rel=nofollow to your internal links to those 90 pages you would be making your 100 page website into a 10 page website as far as Googlebot and other crawlers are concerned.
This would "prioritize" those ten pages.
In most scenarios such crawl prioritization is not really needed, but there do exist situations where this method may be useful to shaping how search engines see your site.
4. Protection from penalization
A big reason that people use rel=nofollow is to avoid search engine ranking penalization.
- Not using nofollow on paid links? - Your ranking will get penalized by Google.
- Not using rel=nofollow on questionable links? - Your ranking may get penalized by Google.
- Not using rel=nofollow in your press releases? - Your ranking may get penalized by Google.
As far as the functionality of rel=nofollow goes, it is for spam protection. As far as the human reality of why nofollow is actually used...
Protection from penalties.
Sometimes this means a webmaster will overuse rel=nofollow rather than risking anything.
How I use rel=nofollow
I use nofollow on this site on just about every page. The manner in which I use it is to notate paid links and affiliate links.
I do not use it on any other links because I am the only author on this website and as such every link is created by me. Therefore there is no risk of unintended links coming from this site (as there would be if I had comments or other user generated content).
The only links I nofollow are the links you see in my sidebar (my sponsors) and the affiliate links in my ads.
I do this to follow the Google webmaster guideline on paid links and advertisements.
- Google help page for nofollow
- Google blog: Disclosing paid reviews
- rel=nofollow HTML5 specification
- Nofollow tool (identifies and displays nofollow links)
- The Google guideline tool (identifies common paid links)