Alias Domains, Rel=”Canonical” and 301 Redirect – Which One Should You Use for Best Results?

Article written by:
  • Search Engine Optimization
  • Updated: May 19, 2015

As we all know by now, the factors affecting SEO are so numerous that it is nearly impossible to be informed of every detail. Nevertheless, we must stay on top of everything that could be important for our optimization efforts. This is why I decided to provide you with the information about alias domains, 301 redirect and rel=”canonical” tags and help you decide which solution is the best one for you.

What Are The Alias Domains?

Alias domains can be set up for domains such as and, or if you want your default domain to be, you can add the as an alias. This is related to the Canonical Name Record and is a type of resource record in the Domain Name System (DNS) that specifies that the domain name is an alias of another.

Theoretically, you can use this system to set up a domain such as as an alias of the domain.

Developers usually turn to this solution because it seems as the easiest solution available. However, it might take a while before the search engines realize the pages are actually aliases and not duplicate content.

Aliasing is not something new, but it now emerged as a way of resolving duplicate content and domain issues. Though it can be used, the 301 redirect and canonical tags are established SEO practices which we know work just fine.

301 Redirect

301 redirect is most commonly used to save SEO authority and link juice when a website is moved to a different domain. The best option is to redirect each page to a corresponding page on the new website, though a dynamic 301 is also possible. This type of redirect can be used to redirect link juice from a deleted page to an existing one as well. It can also be used to avoid certain duplicate content issues and it’s easy to implement.

You can try it on your own, if you have a WordPress website and you are planning to delete some old posts, but you do not want to lose link juice. You should redirect the page you want to delete to another page with similar content. Inserting a piece of code like this one:

redirect 301 /old/old.htm

takes care of redirecting a static page.

As for dynamic page redirect, the following rule can be used

RewriteEngine on
RewriteCond %{QUERY_STRING} ^id=13$
RewriteRule ^/page.php$ [L,R=301]

The id=13 should be replaced with the query string of the page you wish to redirect and the page.php with the name of your file prior to the query string.

For file names with a space you wish to redirect, use

redirect 301 “/old page.htm”


Whereas a ‘301 redirect’ redirects both bots and humans, the Canonical URL tag is just for search engines, which means you can still track visitors to both of the unique URL versions.

For SEOs, canonicalization is used when the same page can be loaded from different URLs. Loading the same page from different URLs is a problem because duplicate content issues are created. This can often happen simply because of the default settings for web servers.

So, for www/non-www versions of websites, this means that the engines need to know which one is canonical, that is, they need to be told that those pages are the same and that the website owner had no intention to play around with Google’s rules. This is done by adding a rel=”canonical” tag to the web page header.

<link rel=”canonical” href=”” />

Common Mistakes in Using rel=”canonical” Tag

When you are implementing this technique, you should avoid making some common mistakes. For example:

  • Avoid applying this tag when you have written, for example, a several page long article. If you apply this tag to point to the first page of the series as the canonical version, no other pages except for the first will be indexed. Instead, Google recommends that in this case you should use one single page containing the entire article as the canonical page or use rel=”prev” and rel=”next” pagination markup.
  • Using relative URL where absolute URL is due is another common mistake. What people often do is use

in the canonical tag. This would mean that your canonical link is actually

You need to either specify it as

or simply as


  • Placing the rel=”canonical” tag inside the <body> tag is another common mistake. Make sure to place it as far up the <head> tag as possible and check all your existing tags to correct any potential mistakes.

Using 301 Redirect or Canonical Tag is Definitely More Recommendable

What I would recommend is using 301 redirect and canonical tag instead of even thinking of marking different domains as aliases simply because you will need to use the established methods anyway.Though domain aliasing is not bad in itself and provides some solutions, as an SEO I would always prefer established ways for taking care of several URLs pointing to the same content.

Using the 301 redirect or rel=”canonical” tag is easier and you will not have to worry. Of course, in some cases aliasing is the right solution for certain problems and no one can deny it can be good and useful.

To confirm my recommendations I browsed different internet opinions on the matter. Though they should be taken with a grain of salt, in this case, they more or less concur with mine. On different forums I have found out that most SEOs agree that a 301 redirect or canonical tag should be added just in case, though their opinions on aliasing differ in intensity. So there you have it – play safe!

Article by WHSR Guest

This article was written by a guest contributor. The author's views below are entirely his or her own and may not reflect the views of WHSR.