Url Capitalization & SEO : How there important to SEO?

Many people are really surprised to learn that URLs are actually case sensitive (unlike the actual domain name). Simply put, while it doesn’t really matter how you spell your domain name (domainname.com or DomainName.com or DOMAINNAME.com), it DOES make a huge difference how you spell your URLs (domainname.com/page1 or domainname.com/Page1).

Let’s say, you have started promoting capitalized version (domainname.com/Page1) because you think it looks prettier and is better to remember. Let me explain what may happen (I guess a table is better to explain this because you can always use it as a cheatsheet):

	domainname.com/page1	domainname.com/Page1
Your site is hosted on a Windows-based server
Header response when requested either of the two	200	200
Google’s reaction	Both URLs will be indexed and ranked. Obviously, this will cause some duplicate content issues but Google will most obviously be able to figure that out (by choosing one of them). What’s more important is that you are wasting plenty of link juice spreading it between the two versions.
Your site is hosted on a Linux / Unix-based server
Header response when requested either of the two	200	404
Google’s reaction	Google will try to index both but will drop the 404-one. Again, you are wasting your link juice in this situation. What’s also important, you confuse your visitors by sending them to the non-existent page.

So what’s the best way to handle the problem?

• While most basic SEOs factor that will recommend sticking to only one version, I recommend to always choose lowercase pattern (just because there will always be people who will link to a more traditional, plain-text version);
• If for some reason you start seeing URLs with capital letters get into index (someone linked to it or you changed your content management system and it capitalized some URLs), use 301-redirect to let people, search crawlers and links go to non-capitalized URLs to avoid any problems.