09th Feb2015

SEO Best Practice: Subdomains or Sub-folders?

by Gyro

When to use Subdomains or Subfolders for better SEO

I follow moz quite a lot, and there is an article that made me think a lot.

5. Subdomains or Sub-folders
Since search engines keep different metrics for domains than they do subdomains, it is recommended that webmasters place link-worthy content like blogs in subfolders rather than subdomains. (i.e. www.example.com/blog/ rather than blog.example.com) The notable exceptions to this are language-specific websites. (i.e., en.example.com for the English version of the website).

This discussion on moz gave an interesting insight as to why moz thinks subfolders are better than subdomains. The first comment is from a moz-staffer:

"We recently were able to test this using a subdomain on Moz itself (when moving our beginner's guide to SEO from guides.moz.com to the current URL http://moz.com/beginners-guide-to-seo). The results were astounding -- rankings rose dramatically across the board for every keyword we tracked to the pages."

Now, consider what Matt Cutts once said:

"A subdomain can be useful to separate out content that is completely different.".

My theory/understanding:

Before moz's move from subdomain to subfolder, google considered their guides as "completely different" content from the content on moz.com. Another factor is that a subdomain has its own PR and DA, so by moving the guides into the main domain, it shared the PR and DA of moz.com and also improved moz.com itself by giving it more pages with relevant content.

My conclusion:

1. If you want to install a blog on your domain with content that is related to your main site, you should put it in a subfolder, so blog and site benefit from each other.

2. If you want to install a blog on your domain with content that is unrelated to your main site, it would make sense to install it on a subdomain, rather than a subfolder.

What do you think?

:)

p.s. I originally posted this in a forum and got an amazing 18 views in 2 months… let's see how many people end up reading it here :)

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