Natural Search Blog

Advice on Subdomains vs. Subdirectories for SEO

Matt Cutts recently revealed that Google is now treating subdomains much more like subdirectories of a domain — in the sense that they wish to limit how many results show up for a given keyword search from a single site. In the past, some search marketers attempted to use keyworded subdomains as a method for improving search referral traffic from search engines — deploying out many keyword subdomains for terms for which they hoped to rank well.

Not long ago, I wrote an article on how some local directory sites were using subdomains in an attempt to achieve good ranking results in search engines. In that article, I concluded that most of these sites were ranking well for other reasons not directly related to the presence of the keyword as a subdomain — I showed some examples of sites which ranked equally well or better in many cases where the keyword was a part of the URI as opposed to the subdomain. So, in Google, subdirectories were already functioning just as well as subdomains for the purposes of keyword rank optimization.

I’ve seen a lot of sites which had varying degrees of quality in their subdomaining strategies. If you do have subdomains, you should ideally insure that they contain primarily unique content not reflected on your other domains — each subdomain should contain page content that does not also live on other subdomains or else it can appear that you are attempting to spam the search engine indices.

Google’s Webmaster Guidelines are very clear on this subject:

“Don’t create multiple pages, subdomains, or domains with substantially duplicate content.”

Most large corporate websites have some level of accidental duplicate content, but if you deploy dozens or hundreds of subdomains with all dupe text, it will appear that you’re purposefully trying to spam the search engines — don’t do it.

If you are considering how to structure your URLs and site content for natural search marketing, I’d say you might be better off just using a simple format of descriptively keyworded directories and subdirectories rather than keyworded subdomains. This is often easier to manage, and it looks a lot more natural/reasonable from the search engines’ perspective. There’s lower likelihood of accidentally mirroring/duplicating your content, too.

Don’t freak out if you have a few subdomains — this is also natural. Many major websites host different site sections and applications on subdomains, and some have external providers delivering content on separate servers — it’s very easy in those cases to assign a subdomain to the third party that’s providing service for you. As long as you’re not duplicating the main content of your pages on the subdomains, this is fine.
Finally, I’ve had a number of people ask my opinion regarding foreign languages — which is better, subdomain or subdirectory.

I actually prefer using separate top-level domains (“TLDs”) for this purpose, since it allows you to send a very clear signal to the search engines that particular content is intended for various countries. For instance, your French language pages could be delivered on .FR domains like:

However, if for some reason you don’t wish to use foreign TLDs for your alternate language pages, you should not worry overly about using separate subdomains versus directory/subdirectories. “” will likely function just as well as “” in my opinion. I believe that translated versions of pages are NOT counted as duplicate content because they essentially contain very different text. Yes, the information may be duplicated, but the text content is not, and pages in two different languages are far less likely to both come us as relevent for the same keyword search.

So, for foreign language pages, I recommend separate TLDs for best performance, or else use whatever approach is easiest for you to set up and maintain.

11 comments for Advice on Subdomains vs. Subdirectories for SEO »

  1. MyAvatars 0.2

    Nice Job Chris,

    Thanks for putting this together.


    Comment by John Ellis — 12/17/2007 @ 8:38 pm

  2. MyAvatars 0.2

    I agree. Additionaly i think there is no matter what to use subdirectory or subdomain. The disicion shoulb be gorund on semantical reason.

    Comment by shuron — 1/25/2008 @ 2:27 am

  3. MyAvatars 0.2

    I would be interested in your opinoon of duplicate content on seperate TLD’s in different countries.

    We rank very well in the US for a couple of keywords, but not so for the same keywords when seaching in the UK.

    If we set up .com and would this be duplicate content ?

    I assume so but trying to understand what Google woudl do with the duplicate ? I guess that Google would rank only one in each region, would that be ranking in UK ?

    Comment by Shane Wallace — 8/6/2008 @ 12:39 am

  4. MyAvatars 0.2

    Nice article. Which would you recommend, subdomains/subfolders or multiple domains?

    Comment by wq — 8/28/2008 @ 8:09 am

  5. MyAvatars 0.2

    This is a very interesting article, I wish I’d found it sooner. I’ve recently set up sub domains of my main site for USA and Canada customers. But having read this article I now think that a sub directory structure would be better as a lot of the content on the sub domains is the same.

    I’ll be having a rethink about it now.


    Comment by Tony — 12/16/2008 @ 6:32 am

  6. MyAvatars 0.2

    This is an interesting article and it’s great that you’ve highlighted the issue. One of the challenges we’ve faced is that our site is split across a number of important sub-directories, driven by the nature of the products we sell. To that end we’re focusing our optimisation efforts on the sub-directories themselves.

    @ Shane – it is possible to rank well both on and UK for the same phrases, with the same site. What we’ve found critical is building up good links from each country, so that the link profile is about equal.

    Comment by Scotweb Kilts — 1/29/2009 @ 11:56 am

  7. MyAvatars 0.2

    As a novice at this game, I needed your advice. Does your advice about not using various sub-domains on substantially the same content apply also to sub-directories?

    I picked my URL name before I knew much about search engines and keywords. Now I’m thinking about making one or two new URLs with the same name plus a /keyword after it and with the same content as the original Website. Is that acceptable or BAD?

    Comment by Harold Post — 2/5/2009 @ 5:24 pm

  8. MyAvatars 0.2

    It’s bad. Duplicate content, same language… the search engines will definitely frown upon that.

    Comment by Rise Interactive — 4/6/2009 @ 9:18 pm

  9. MyAvatars 0.2

    Thanks for the nice post on a confusing topic in the SEO arena.

    I guess I would go for separate TLDs too as you proposed. Although there will be some level of dup content, I don’t think it’s a concern. The SEs typically surf up the most relevant pages, so if 2 TLDs are contending for the same KWs, the SEs would rank 1 and drop the other, which should be fine as a net result.

    Comment by Andy — 6/1/2009 @ 8:53 am

  10. MyAvatars 0.2

    Thanks for the nice article and clearing things up a bit on this matter. Thankfully, we’ve never need to get into this. In anycase, i tend agree with some of the folks that dup content is a non-issue if the keywords targeted are not the same

    Comment by Office Stationery — 1/5/2010 @ 10:01 am

  11. MyAvatars 0.2

    Hi, I get the idea, but I’m still interested in using a subdomain.

    I’m googling around for a way in which I’d make the content of a subdomain to not show up in the main domain that is: sub.domain. com not to show up as domain. com/sub Have any ideas?

    Comment by Boniface Mkenya — 6/17/2011 @ 10:13 am

Leave a comment

* Do not use spammy names!

RSS feed for comments on this post. TrackBack URI

RSS Feeds
Aug Sep Oct Nov
Jan Feb Mar Apr
Jan Feb Apr May
Jun Jul Aug Sep
Oct Nov Dec  
Jan Feb Mar Apr
May Jun Jul Aug
Sep Oct Dec  
Jan Feb Mar Apr
May Jun Jul Aug
Sep Oct Nov Dec
Mar Apr May Jun
Jul Aug Sep Oct
Nov Dec    
Jan Feb Mar Dec
May Jun Jul Aug
Sep Oct Nov Dec