Use of rel=”nofollow” for SEO: How and Why?

Today, I’m going to summarize observations on technical ways to generate hyper links,  use of rel=”nofollow” on anchor tag, and it’s impact on SEO and sometimes even on user experience.

What is rel=”nofollow”?

It got so popular that it even got it's T-shirt.

Why NoFollow deserves a T-shirt?

Let’s start with a typical hyperlink which would look as follows:
<a href="url-goes-here" title="describe-link-here">Anchor-Text-Goes-Here</a>

If we add a a value of “nofollow” on rel attribute on <a> anchor tag, then that link would be considered a NoFollow link. As in  example below:
<a href="url-goes-here" rel="nofollow" title="describe-link-here">Anchor-Text-Goes-Here</a>

“NoFollow” gives webmasters a way to communicate with Search Engines the importance or trust a link might carry.  In other words, it’s an instruction to search engine bots not to crawl a particular link, or to discount the link value it might otherwise carry. In layman’s terms, by using a NoFollow link, webmasters communicate to Google something like “Don’t crawl this link”, or “Even if you crawl the link, don’t pass SEO juice onto the next page”, or “I think this link is interesting, but I cannot vouch for it 100%”. There is no 100% guarantee though on how Search Engines (Google, Bing, Yahoo, Ask etc) interpret that cue and how exactly would they use such recommendation. More on that later in next blogs.

Nofollow for whom? Google or Businesses?

Let’s quickly talk about the need of rel=”nofollow”. Google states following 3 use cases for NoFollow:

  • Untrusted Content
  • Paid Links
  • Crawl Prioritization

The first two reasons for mostly for Google, while the 3rd one is probably more important for eCommerce websites. To expand a bit more, blog comments and forum postings (including forum registration names) could be examples of untrusted contents on websites. When Google bots were not “smart enough” few years ago, they needed rel=”nofollow” to identify such blog and forum links so the value of such poor links could be discounted. Similarly, not taking SEO credit from a paid link is what Google urges by utilizing NoFollow, so that they could pass “right” amount of SEO juice for “correct” organic rankings on SERP.

Purely, from an eCommerce’s perspective, the third reason of  “Crawl Prioritization”  is probably the most valuable for a business. As Google (and Bing for that matter) has limited crawl budget for each website, businesses would want to make sure that limited time is invested fully to discover all of their fresh and valuable content (through high search volume anchor texts).  So the use the “NoFollow” allows webmaster to control how Google’s robots might behave on their websites. In addition, as the total value of SEO on each page is diluted by the number of links on a page (very simply stated here, it’s lot more complex), with strategic use of NoFollow, webmasters can help inner pages get better SEO juice, hoping higher ranking for deeper pages on relevant terms.

3 Types of Links from SEO Perspective:

Now, it’s time to jump into how links can be generated in various ways:

1) Follow links
The link below is a follow-link, and is passing the SEO juice.
<a href="url-goes-here" title="describe-link-here">Anchor-Text-Goes-Here</a>

The link may have other attributes such as a CSS class, or target or few others as needed. Still a follow-link.
<a href="url-goes-here" title="describe-link-here" class="style-name" target="_blank">Anchor-Text-Goes-Here</a>

2) JavaScript links
In some websites, JavaScript is used to create links. Yes, in past a lot, however, even today in 2014, there are many renowned websites, using well intentioned JavaScript to build/generate links for various reasons including SEO. (Real life examples are intentionally omitted here. Contact me via comments box below to discuss more.)

Problems with JavaScript links:

  • SEO: Search Engine cannot follow JavaScript links. So, when links are created by JavaScript, we’d seem to present a link to customers but no link to Google. So Google cannot crawl those links. When done rampantly, it might even appear as presenting 1 set of data to human readers and a different set of data to Search Engines, whether intentional or not, it might raise gray hat questions. For link ssculpting, use of JavaScript links is mostly questionable. (Correct way is to use Nofollow link. See below.)
  • Poor User Experience: CTRL+Click (and Command+Click on Macs), does not open the link in new tab/window if a link is JS based (though, there is a simple fix, it’s still a flawed use.). This prevents users on an eCommerce site from comparing multiple products by looking at them in multiple tabs. With JS links, we could be blocking common practices expected by customers resulting in poor customer experience. This can be easily improved by using NoFollow links.
  • HTML source code is unnecessarily long (poor content to code ratio), takes more time to load (Page Load time issues), and overall HTML gets inferior and less efficient.

Here are the few additional problems on relying on JavaScript code to generate links (though this only applies to a much smaller set of population).

  • JavaScript Disabled Browser:  If JavaScript is disabled on your customers’ browser when they visit your website, they will encounter a non-functioning links. In one of the websites (example not published for anonymity), the entire top left Navigation was missing! (Customers would see a big blue box with nothing on it, where the site’s primary navigation is intended. On Level 1, Level 2 category pages, as well as product pages, customers would see the click-able links (due to CSS class) however when clicked, NOTHING would happen. Imagine the frustration on customer’s part when a click does not go through, a new page won’t load when expected.)
  • ROI of JavaScript based links: Only about 2% of population have JavaScript disabled browsers in US and EU, so one might argue, it’s not such a big deal, however, I’d suggest to multiply 2% of traffic visitors * average conversion rate * average AOV to find out lost revenue due to JavaScript links. You might be lucky or not so lucky based upon your industry.
Finally, the take-away here is we have ask why do we ever need to create JavaScript links.  There are good reasons for it, but SEO, in most cases, is not.

3) NoFollow links:
rel=”nofollow” can be strategically used throughout the website to manage Crawl Prioritization as well as to “control” passing of SEO juices in best possible ways. It eliminates the need to have JavaScript hide the links from Google Bot’s view, rather allows to clearly communicate why there is no need to crawl a link or pass any SEO juice for whatever reason (read Internal Link Sculpting). NoFollow links are very commonly found in blog comments, and forum registrations. Even, Wikipedia has started to use NoFollow on all of its outbound links as well, so are many blogs and other websites now apply NoFollow automatically on all outbound links. NoFollow can be built into pretty much any CMS.


Use following guidelines and as needed update your existing server side codes to generate following HTML in your websites:

  • Follow links:<a href=”url-goes-here” title=”describe-link-here”>Anchor-Text-Goes-Here</a>. Use cases, all links in general.
  • No Follow Links: <a rel=”nofollow” href=”url-goes-here”  title=”describe-link-here”>Anchor-Text-Goes-Here</a>. Use Cases: User generated links, Outbound links, Repeated links, Links with generic keywords such as “More Information” etc.
  • JavaScript links – Limit JavaScript links to only wherever it’s absolutely needed such as for dynamic HTML or JSON calls, or AJAX requirements etc. Use Cases: Form validation, shopping cart etc (as appropriate).
Here is a nice infographics by Search Engine Land  that can be printed easily. Should I take time to add “NoFollow” on this outbound link?
Despite all these, the controversy still remains – has the internet become less “spammy” due to the NoFollow? What do you think?

About Ujjwal Bhattarai

Ujjwal is an engineer by education, a programmer by hobby, and an internet marketer by choice. Other than 1 minute chess, and biking, his passion includes SEO, SEM/PPC, CRO, and Web Development. As a lifelong student of Internet Development, he is hopelessly addicted to Internet, and sincerely believes after fire, wheel, and decimal point, internet is the fourth most important invention in the human history. Catch up with him on Twitter at @uj2wal or at his Google+ .


One comment on “Use of rel=”nofollow” for SEO: How and Why?

  1. saiful on said:

    Thanks for helpful information.

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