When should I use a trailing slash in my URL?

Question

When should a trailing slash be used in a URL? For example - should my URL look like /about-us/ or like /about-us?

I am fully aware of the SEO-related issues - duplicate content and the canonical thing; I'm trying to figure out which one I should use in the context of serving pages correctly alone.

For example, my colleague is thinking that a trailing slash at the end means it's a "folder" - a "directory", so this is not a correct style. But I think that without a slash in the end - it's not quite correct either, because it almost looks like a folder, but it isn't and it's not a normal file either, but a filename without extension.

Is there a proper way of knowing which to use?

Answer 1

Other answers here seem to favor omitting the trailing slash. There is one case in which a trailing slash will help with search engine optimization (SEO). That is the case that your document has what appears to be a file extension that is not .html. This becomes an issue with sites that are rating websites. They might choose between these two urls:

• http://mysite.example.com/rated.example.com
• http://mysite.example.com/rated.example.com/

In such a case, I would choose the one with the trailing slash. That is because the .com extension is an extension for Windows executable command files. Search engines and virus checkers often dislike URLs that appear that they may contain malware distributed through such mechanisms. The trailing slash seems to mitigate any concerns, allowing the page to rank in search engines and get by virus checkers.

If your URLs have no . in the file portion, then I would recommend omitting the trailing slash for simplicity.

Answer 2

I'm always surprised by the extensive use of trailing slashes on non-directory URLs (WordPress among others). This really shouldn't be an either-or debate because putting a slash after a resource is semantically wrong. The web was designed to deliver addressable resources, and those addresses - URLs - were designed to emulate a *nix-style file-system hierarchy. In that context:

• Slashes always denote directories, never files.
• Files may be named anything (with or without extensions), but cannot contain or end with slashes.

Using these guidelines, it's wrong to put a slash after a non-directory resource.