One question that one of my customers raised on one occasion was where he should store his localized web pages. In his root directory, together with the pages on the original language? In a subdirectory? Or perhaps in a subdomain? I admit that at first I was thinking about what a stupid question that was, but then I realized that it was not so stupid at all. And many webmasters will have to face this question repeatedly, so I penned it down as the subject for a future post. Well, the time for such post has come.
The root directory of the website is the main location where most of the pages are stored, so it seems a logical candidate, as we will get pages such as www.mydomain.com/localized-page.html. This improves readability and makes the link easier to understand, but also maintains the page rank of of the original site.
On the other hand, placing the localized pages in the root directory implies mixing all the pages. This is bad in the sense that administration of the site becomes more complicated, both because the number of pages increases and also because we have pages of different languages mixed in one single place. It is bad enough if you have a few dozen pages, but for big sites it’s plainly unmanageable. This complicates the update of the site, as it is unlikely that the same person will update the pages in all different languages, and simply finding the pages in one of the languages becomes difficult. There is also an issue about what a search machine will think when it find pages from different languages in a same directory.
One last problem is that even if you localize the file names of the translated pages (which you should always do, as localized html file names improve your SEO ranking) there are cases where the name will be the same in the source and target language. True, there is only a limited number of cases, but they occur. And this means that a localized page might have to use a different name, which perhaps does not score as well as it could.
Subdirectory (also called folder)
You can also place your localized pages in a folder within your website. This is another option that maintains the page rank of the original site, but makes the pages less evident. For example, if you have an “ES” subdirectory for the Spanish pages, your localized pages would be www.mydomain.com/ES/localized-page.html.
The obvious advantage is that, being on the same site, it maintains the same site authority as the original site. It also allows to group the pages in one specific language, hence making it easier to maintain them. You can also manage the global site easier, for you can use for example the same robots.txt file, the same site map and many other common features.
On the other side, you complicate the global URL (as you have to add the new directory between the site name and the page name), making it more difficult to remember. The problem of a search machine finding pages in different languages in the same folder would be also obviously avoided.
A subdomain is different from a folder or directory in the sense that it is a domain of its own. An example would be ES.my-domain.com, which could correspond to the Spanish subdomain of my-domain.com. Though often the subdomain is created in a folder below the main domain, a subdomain resolves in the domain name system (DNS) as if it were strictly speaking a separate domain -which it is- and might be even stored in a separate server, which beginners will find extremely complicated.
The big advantage of this is obviously that you will have a “separate” website for your localized pages, which comes in handy when you have things like localized scripts that you could not easily mix with the ones in the original language. When you need updating, you also know that absolutely everything below this subdomain is translated, and hence you can work on it separately without worrying about potential interferences with the parent site.
The big disadvantage is obviously exactly what you were thinking: If you use a subdomain for the localized site, it’s exactly the same as if it were a different domain. And that means managing two domains, no domain authority inherited from the main site (except through the links from it) and if you decide to change the subdomain name or convert it into a folder then all off-page SEO is lost.
So in principle a subdirectory seems more advantageous than a subdomain. But what do the search engines think? In the Google Webmaster Central Blog they point out that both subdirectories and subdomains are both recommended solutions.
Ultimately, I agree with the stated by Matt Cutts in a blog on the same subject: That you should reserve subdomains for things that you offer, but are not necessarily related to your main site. In all other cases, use subdirectories, not only because it is more convenient for site management purposes, but also because the localized site can best retain the site authority of the original site.
The only exception I can think of is that if you think that traffic in one of the localized versions might grow so much that it might require a server of its own, it is much easier to move a subdomain than a subdirectory to a different server.
There is obviously a different solution, which is using a language-specific top-level domain (TLD), but I think that merits a post of its own…