How and When to Use 301 Redirects vs. Canonical

In the world of SEO, web page redirection seems like a bit tricky. 301 redirection and canonical options create confusion for SEO practitioners. Site owners face frequent issues such as, "When to use 301 redirect? And when to use rel="canonical" attribute?” These two methods are used to conquer duplicate content issues and to improve user search experience.

What is the difference between 301 Redirects and Canonical

301 redirection tells search engines that, the page is no longer available here and moved permanently to new location. The page automatically redirects to new location and tell search engines to remove the page from their index and pass credit to new page. On the other hand, rel=canonical is the simplest way to tell Google that, the version has set of pages or content and to index only the preferred version of page.

301 Redirects - What are they?

A 301 redirect is a server side redirect, designed to tell search engines and users that page has been permanently relocated to new location and the previous page no longer exists. With the use of this command, the new page gets original link popularity, relevance and ranking power. Matt Cutts stated that, by implementing 301 redirects technique, "you will lose just a lit bit, not very much at all".

What it does for users

Most probably, user never notices that URL was redirected to new one unless they look at change in URL while browsing. If they get relevant content then they are unlikely to be affected even if they spot the change. 

So, in user point of view, there is no problem with 301 redirect. 301 redirect option is fine as long as it doesn't confuse users.

What it does for the search engines

When search engines find a URL with 301 redirect, they redirect to new page and index the old page. Google has to pass existing link juice to new URL, but most probably it won't pass 100% link juice. Search engines need to remove old page from their index and moreover, it takes little bit of time but no longer than a weeks.

When you should use 301 redirect

You need to use 301 redirect techniques when you are planning to move domain to new domain or changing URLs to new structure. If you want to implement 301 redirect technique for new design or structure and you don't want users and search engines to look at the old page in such case you can use 301 redirect option. You have to follow Google guidelines before implementing 301 redirect methods.

You can even use 301 redirect, if your webpage contains expired content such as old products, old terms and conditions, products which has no relevant content and of no use to users. In addition, you need to look at few points while removing expired content from your website.

1.First, check analytics to see the content has any search traffic, if it does, then what is the use of redirecting the content? In turn you may potentially lose search traffic.

2.Check whether your website has another page which has similar content that contain user relevant information. If it does, then use a 301 and point out to the similar pages. Through which you can able to retain the traffic back.

3.At last, check whether the content could be useful in future? 

If multiple versions of web page served for a unique purpose, it would be better to use rel="canonical" attribute instead of 301 redirect.

Rel=canonical tag - When and how to use it

The rel=canonical attribute is useful for search engines. It is an HTML tag that enables website owners to conquer duplicate issues by mentioning "canonical" or preferred version of webpage.
For Example: If the webpage is available in both web version and print version, then place rel=canonical tag in the print version and show search engines the web version is the preferred choice and it is most important for users.

Where 301 may not be possible:

In few cases, implementation of 301 redirect can be tricky; developers don't know how to use it. In such situation it is bit easier to use rel=canonical tag because there is no need of involvement in server side. It is quite easy, you can just place rel=canonical attribute in head tag on the page.

Example:
www.phoneshop.com/smartphone/3G

www.phoneshop.com/3G/smartphone

Here, both the pages could return to set off same results and where you can find duplicate content pages. So, in this situation, 301 redirect wouldn't be possible and appropriate. Hence, rel=canonical would work better in this case.

When to use Canonical

When 301 wouldn't be possible, or take too much time.
If you want to keep duplicate content and cross-domain considerations live.
Dynamic pages with multiple URLs of a single page.

Conclusion

According to Matt Cutts statement, even though rel= canonical attribute is a directive that Google usually follows, 301 redirect is preferred wherever possible. You need to be more cautious while using these two methods because as these changes may easily go wrong if not used properly and even it can harm your website in search results.