What are ‘nofollow’ tags and when should they be used in SEO?

‘Nofollow’ tags are an HTML attribute that tells search engines not to pay any attention to links that appear on a webpage.

It was created in 2005 by the major search engines as a way of combatting link spam and dodgy SEO practices, though its impact in helping to win that fight is debatable.

Recently I’ve had a few conversations around the use of nofollow tags so thought it would be helpful to give an overview of why they’re important and in what context they should be used.

By David Moth December 6th 2013 16:39

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What’s the point in nofollow?

A nofollow tag is a simple piece of HTML code that tells search engines not to follow a particular hyperlink.

Normally a link to an external site would have SEO benefits for that site, however the nofollow tag means that search engines ignore the link and don’t ascribe it any value in their algorithms.

In the words of Google’s Matt Cutts:

Rel=‘nofollow’ means the PageRank won’t flow through that link as far as discovering the link, PageRank computation, all that sort of stuff.

Adding in a nofollow tag

As mentioned, nofollow tags are easy to implement as it only requires a simple bit of HTML code.

So for example, a hyperlink without a nofollow tag would look like this:

link

While this is what it looks like with a nofollow tag:

link

The tags can be added in manually but thankfully many content management systems, such as WordPress, automatically insert them where relevant.

And here are some examples of when it might be useful to implement nofollow tags…

Adverts or paid links

Paid links are obviously a terrible idea for SEO as it will likely lead to your site being penalised by Google for dodgy practices.

However adverts and paid links can still be a useful way of driving traffic back to a particular site, so marking them as nofollow allows you to deliver traffic without running the risk of being slapped with a penalty by Google.

Internal links

In a recent Webmaster Help video Google’s Matt Cutts answered a question about whether some internal links should be tagged as ‘nofollow’.

His advice was that in general it’s a good idea to allow Google to crawl the entire site, stating:

I would try to leave the ‘nofollow’ off, so if it’s a link from one page on your site to another page on your site, you want that PageRank to flow, you want Googlebot to be able to find that page.

However in the case of large websites it might be a good idea to add nofollow tags to generic pages such as ‘contact us’ or the ‘sitemap’, as this will give higher priority to links pointing towards more valuable content.

Blog comments

It’s common for publishers and site owners to automatically tag all blog comments as nofollow so that search engines ignore any links posted by users.

It is basically a way of preventing spammers from gaining any SEO benefit from sneakily publishing links on your site.

That’s not to say that using nofollow tags will actually deter spammers from posting pointless comments stuffed full of links, as we know all too well at Econsultancy.

Links to competitors

If you find yourself in the unfortunate position of having to link to a site that competes for similar search keywords, then definitely stick a nofollow tag in so that you’re not helping them out.