Does anybody know what the best SEO practice and most effective format for URLs is currently?

All lowercase or mixed case? Example:



  • 1
    this seems like an edge case for 'programming question'
    – KevinDTimm
    Oct 14, 2010 at 20:10
  • I suggest we leave it open. The ideas of premature optimization are certainly part of programming, and if hand-wringing over the case of URL query strings isn't premature optimization, I don't know what is.
    – Andy Lester
    Oct 14, 2010 at 20:28
  • Well, technically it belongs on webmasters.stackexchange.com but I think this has already been asked and answered there so will end up closed... Oct 15, 2010 at 2:10

3 Answers 3


Search engines do care about case.

Capitalization doesn't affect your rankings directly; however, if you have links to a page both in caps and lowercase, the search engine will view it as two distinct pages. You begin to run into duplicate content issues. Depending on your server, example.com/Page1 and example.com/page1 are two different pages, but search engines will always view them as separate URLs.

From a usability perspective, use lowercase. As a user, I don't want to pay attention to capitalization when I'm typing in a URL.

  • +1, don't know about SEO, but I as a user I agree: plz do not force me to pay attention to cases in urls!!! Nov 15, 2010 at 11:34
  • +1, I have experienced this first hand multiple times, search engines do care about case. Apr 4, 2014 at 20:33

Search engines don't care about case.

Rather than navel gazing about whether you should use mixed case or all lower, work on real search engine optimization, which is creating content that give people a reason to visit your site.

  • We really don't know for sure what algorithms are used to assign a score to a page so we really can't say definitively, that search engines don't care about case because nobody knows except for the folks at Google. For example, It may matter that the text between the <a></a> tags maps to a page with the same text and case...
    – Slinky
    Oct 14, 2010 at 20:49
  • It may matter, but it doesn't. And if "nobody knows except for the folks at Google," then why are you asking here?
    – Andy Lester
    Oct 14, 2010 at 20:51
  • Since Google isn't going to tell me explicitly, I am trying to get a consensus on what other programmers have used and seen success with when it comes to URL rewriting. I have my own theories based on my own experience and I am interested in other programmers' experience on this topic
    – Slinky
    Oct 14, 2010 at 20:59
  • 2
    @Slinky: if there was any noticeable difference it would have been picked up by SEOs and be common knowledge by now. Oct 15, 2010 at 2:12
  • @Slinky consistency is what matters. Multiple variations of the same URL are treated as individual pages - which splits your ranking.
    – user18960
    Dec 6, 2012 at 19:12

The way you show the URL you gave as an example, the "what is my site" part would be a directory, not a file name! Also, regardless of what these fools told you, you should always use lower case when specifying your URL's. Likewise, stay away from "dynamic" URL's (URL's created with scripts or programming languages such as PHP of JSP), instead use text readable URL's without all kinds of "+" or "?" symbols that no one including search engines can hardly read.

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