Google Data

Webmaster Level: Intermediate

That is the question we hear often. Onward to the answers! Historically, it’s common for URLs with a trailing slash to indicate a directory, and those without a trailing slash to denote a file:

http://example.com/foo/ (with trailing slash, conventionally a directory)
http://example.com/foo (without trailing slash, conventionally a file)

But they certainly don’t have to. Google treats each URL above separately (and equally) regardless of whether it’s a file or a directory, or it contains a trailing slash or it doesn’t contain a trailing slash.

Different content on / and no-/ URLs okay for Google, often less ideal for users

From a technical, search engine standpoint, it’s certainly permissible for these two URL versions to contain different content. Your users, however, may find this configuration horribly confusing -- just imagine if www.google.com/webmasters and www.google.com/webmasters/ produced two separate experiences.

For this reason, trailing slash and non-trailing slash URLs often serve the same content. The most common case is when a site is configured with a directory structure:
http://example.com/parent-directory/child-directory/

Your site’s configuration and your options

You can do a quick check on your site to see if the URLs:

1. http:////
   (with trailing slash)
2. http:///
   (no trailing slash)

don’t both return a 200 response code, but that one version redirects to the other.

• If only one version can be returned (i.e., the other redirects to it), that’s great! This behavior is beneficial because it reduces duplicate content. In the particular case of redirects to trailing slash URLs, our search results will likely show the version of the URL with the 200 response code (most often the trailing slash URL) -- regardless of whether the redirect was a 301 or 302.
• 
  
• If both slash and non-trailing-slash versions contain the same content and each returns 200, you can:
  • Consider changing this behavior (more info below) to reduce duplicate content and improve crawl efficiency.
  • Leave it as-is. Many sites have duplicate content. Our indexing process often handles this case for webmasters and users. While it’s not totally optimal behavior, it’s perfectly legitimate and a-okay. :)
  • Rest assured that for your root URL specifically, http://example.com is equivalent to http://example.com/ and can’t be redirected even if you’re Chuck Norris.

Steps for serving only one URL version

What if your site serves duplicate content on these two URLs:

http:////
http:///

meaning that both URLs return 200 (neither has a redirect or contains rel=”canonical”), and you want to change the situation?

1. Choose one URL as the preferred version. If your site has a directory structure, it’s more conventional to use a trailing slash with your directory URLs (e.g., example.com/directory/ rather than example.com/directory), but you’re free to choose whichever you like.
   
2. Be consistent with the preferred version. Use it in your internal links. If you have a Sitemap, include the preferred version (and don’t include the duplicate URL).
   
3. Use a 301 redirect from the duplicate to the preferred version. If that’s not possible, rel=”canonical” is a strong option. rel=”canonical” works similarly to a 301 for Google’s indexing purposes, and other major search engines as well.
   
4. Test your 301 configuration through Fetch as Googlebot in Webmaster Tools. Make sure your URLs:
   http://example.com/foo/
   http://example.com/foo
   are behaving as expected. The preferred version should return 200. The duplicate URL should 301 to the preferred URL.
   
5. Check for Crawl errors in Webmaster Tools, and, if possible, your webserver logs as a sanity check that the 301s are implemented.
   
6. Profit! (just kidding) But you can bask in the sunshine of your efficient server configuration, warmed by the knowledge that your site is better optimized.

Written by Maile Ohye, Developer Programs Tech Lead