26 January 2009

Q&A: What is the Nofollow Link Attribute?

Q&A: What is the Nofollow Link Attribute?

Satish asks:

Most blogs use nofollow in the comment section, but I see Google showing even those comments made by me in their Result page!

Then whats the meaning of nofollow ?

I know that its good, if Google indexes my blog URL even from the comment section. But I am getting confused about the meaning of nofollow now.

You are confusing “noindex” with “nofollow.” In order for your comments to not show on the results page of Google, the owner of that blog would need to use a meta robots tag with the “noindex” attribute, which looks like this:

This meta tag tell search engines that they should not index that page, and therefore not include it on the search results.

What most blogs use on the comment author link, on the other hand, is a “nofollow” attribute. A link with a “nofollow”, also called link condom, would look like this:">link text

When a search bot comes across such a link, it will know that it should not crawl the site on the other end (at least not due to this link). Additionally, this link will not be counted toward the PageRank of the site that is receiving it. Here is what Google it does when it comes across nofollowed links:

We don’t follow them. This means that Google does not transfer PageRank or anchor text across these links. Essentially, using nofollow causes us to drop the target links from our overall graph of the web. However, the target pages may still appear in our index if other sites link to them without using nofollow, or if the URLs are submitted to Google in a Sitemap. Also, it’s important to note that other search engines may handle nofollow in slightly different ways.

When should you use the “nofollow” attribute to comply with Google’s guidelines? In three situations:

  1. when you are not sure about the quality of the content on the site that you are linking too
  2. when someone paid for the link (i.e. a company buying advertising on your blog)
  3. when the page at the end of the link is not crawlable (i.e. a login link that leads to a password protected page)

So why blog owners use the “nofollow” attribute on the comment section links? Because they can’t verify the quality of the sites of everyone that is going to post a comment. In order to avoid linking to spammers or bad neighbors, they just nofollow the links.

Notice that there are two ways to add the “nofollow” attribute to the links on a page. You can do it globally via a meta tag, and make all the links inside that page nofollowed, or you can do it locally and add the “nofollow” attribute only to specific links.

The first requires the following code added to the head section of your site:

The second one is equal to the link example we highlighted before.

No comments: