301 Redirects vs. Rel=Canonical

By Nelson Hudspeth | May 31, 2013
More Articles by Nelson

There is a pervasive issue in the world of SEO practitioners, website owners and search engines alike: canonicalization. When should you use a 301? When do you need a Rel=Canonical tag? This post will highlight the differences between the two, and explain what circumstances work best for each.

301 Redirects – What are They?

A 301 redirect is a server-side redirect designed to help users and search engines find content that has moved to a new URL permanently. These redirects pass between 90-99% of the link juice to the redirected page, and according to Google, are the best way to ensure that users and search engines are directed to the correct page.


301 redirects are very useful in the following instances:

Moving a Site to a New Domain

You should use 301s if you are either moving your website or changing the structure of your URLs. With new design or structural changes, you don’t want users or search engines seeing the old version of your site.

Multiple Versions of the Homepage

301s are useful when your home page can be reached in multiple ways, the most common of which is where “www” (is, and is not used) – for instance:



It’s a best practice to pick one of these URLs as your preferred destination and use a 301 redirect to send traffic from the other. In this case, the preferred URL would be www.search-mojo.com.

Expired Content

If you have old content on your website such as old products, outdated privacy policies or old blog/news items, you should consider a 301 redirect rather than a 404, so you’re able to retain the majority of that link equity. 301s also help demonstrate to search engines that your site is up-to-date. A few things to keep in mind in this scenario –

  • You want to redirect these pages to the most relevant page. Consider what would result in the best user experience.
  • You want to be sure you’re redirecting to a page that is likely to stay on the site and stay relevant for the foreseeable future.
    • You don’t want to have to 301 a 301… Google does not like that.
    • Consider redirecting to a higher level page, like a product category page, as these are generally relevant and unlikely to change.

Rel=Canonical Tags – What are They?

A canonical page is the preferred version of a set of pages with similar content. The rel=canonical tag is a way to tell Google that one URL is the same as another URL for search. This code snippet is inserted in the <head> section of the web page’s code. It specifies which page is the original, and therefore, passes-on the link value and appropriate accreditation.

The format for a rel=canonical is:  <link rel=”canonical” href=http://www.search-mojo.com /> and it is to be placed in the <head></head> section of the page.


Rel=canonical tags are very useful in the following instances:

When Dynamic URLs are Generated Every Visit

These would be URLs that are generated depending on how a user goes through your website; something that is pervasive in E-commerce. Another example would be adding tracking code to the end of a URL to measure certain variables like: clicks from certain ads/links, URL paths for conversion attribution purposes, etc.


When 301s Aren’t Possible

There are instances, while rare, where 301 redirects aren’t possible. Occasionally the CMS doesn’t have the ability to do this, or maybe your web developers aren’t as tech savvy as they think they are. A rel=canonical is much easier than a 301 to implement on site, as you only need to edit the <head> tag on the page for it to take effect, rather than making changes server side (which is required with a 301).

Syndicated Content

In late 2009, Google announced support for cross-domain use of rel=canonical. Publishers using the content you wrote should include the rel=canonical link on their pages pointing back to your original document, so that only one version of the content is eligible for ranking.

*Keep in mind* The rel=canonical tag is a “suggestion” to the search engines. According to Google:

rel=canonical options let site owners suggest the version of a page that Google should treat as canonical. Google will take this into account, in conjunction with other signals, when determining which URL sets contain identical content, and calculating the most relevant of these pages to display in search results. Rel=canonical is seen as a hint, but not an absolute directive like a 301 redirect.

Which is Better?

Google’s own Matt Cutts answered this very question in a Google Webmaster Help video in which he confirms that: although rel=canonical is a directive that Google generally follows, 301 redirects are to be preferred whenever/wherever possible.  You should be cautious when using either 301s or a rel=canonical, as these changes can easily go wrong if not implemented correctly, and hurt your website as a result. Regardless of the path you choose, be the “master of your domain”!

Do you have any 301/Rel=canonical success stories? Comment below, or drop me a line @Nhudspeth4!

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