Implemented to prevent comment spamming and other black hat techniques, the Nofollow attribute appeared in 2005. Today, this attribute is used to inform search engines not to follow a link and thus not distribute any page rank to the destination page. On the other hand, the follow attribute tells search engines to follow a link and preserve link equity. This increases the signaled importance, or PageRank, of the target page.
With Oncrawl, you can easily check the breakdown of different types of links on your site. You can monitor your internal and external links, and track whether they are are "follow" or nofollow links.
For instance, if you click on the part of the circle corresponding to Internal follow links, you will access a more detailed report in the Oncrawl Data Explorer with your URL data and additional metrics.
Best practices for using the nofollow attribute on links
In order to prevent from spams and black hat techniques, you should use the nofollow attribute, even if it doesn’t pass any PageRank. You should use it in the following situations:
For paid links: if you do not want Google to penalize you for paid outbound links even if you know these quality links will drive traffic to your website
Comments: if you are not doing any comments moderation, they could contain harmful links. Use NoFollow to prevent your website from commenters publishing bad links
User Generated Content: as the previous one, if you let people contribute to your website without any moderation, NoFollow can help you protect your content from fake links
Embeds: use NoFollow if you are loading videos or infographics you do not want to favor
Duplicate content: you might not want to see your PDFs ranked by the search engines for instance since they are duplicated with the same HTML
Even if the nofollow attribute does not pass any link equity, those links can still bring a qualitative referral traffic. Also, Google gives attribute to other criteria like social signals that are delivered by social platforms like Facebook or Twitter, even though they are generally nofollow links. Even these links can help you build trust.
How to implement a nofollow attribute
To transform a regular link into a nofollow one, add an attribute in the form of a short code within the link tag in the source code of your page.
<a href="http://www.example.com/">link to a page</a> will become
<a href="http://www.example.com/" rel="nofollow">link to a page</a>.