File Extensions

From Well Designed Urls WiKi

This page is for information about URLs and File Extensions

Contents 1 Discussion 2 External Links 3 Mike Schinkel's Opinion 4 Example URLs 5 Footnotes

Discussion

There is an active discussion on the mailing list on this topic:

• http://tech.groups.yahoo.com/group/welldesignedurls/msearch?query=file+extensions

External Links

• A case against file extensions
• File Extensions on Blog Entries Do not Leak Implementation Details

Mike Schinkel's Opinion

In my current opinion HTTP URLs:

• SHOULD NOT HAVE file extensions for web pages of the HTML/XHTML Content Types (i.e. anything that the browser interprets as an HTML page it can render.) See URL 1. for an example.
• SHOULD HAVE a trailing slash ("/") on all URLs that do not have a file extension. [1]
• SHOULD, issue a Permanent (301) Redirect whenever a URL is requested that has no extension. Users generally don't understand the distinction and get confused between a URL like URL 1. and URL 2. [2]
• SHOULD HAVE file extensions for Content Types for most other files (i.e. GIF, JPG, PNG, PDF, ZIP, EXE, etc.) If these files do not have extensions it can confuse users who may want to save or otherwise interact with them. See URL 3, 4, & 5. for examples.

I am continuing to do research on this subject and plan a signifcant blog post article at blog.welldesignedurls.org.

Example URLs

1. http://www.example.com/my-topic/
2. http://www.example.com/my-topic
3. http://www.example.com/images/logo.gif
4. http://www.example.com/my-topic/whitepaper.pdf
5. http://www.example.com/downloads/demo.zip

Footnotes

[1] - An observant person will notice that this wiki does not follow the recommendation of using a slash at the end of its URLs. The reason we (currently) do not is because (Mediawiki) cannot be configured to serve URLs of this type without modifying the source code. Though we'd prefer not to touch the source code (or we'll own it), we neverless haven't had the time to do so. Once again, it is the software vendors and open-source project members are the most to blame for the Epidemic of Poorly Designed URLs. OTOH, if you are reading this and would like to help, please let me know.

[2] - Further, it is rarely if ever necessary to have a file w/no extension and a directory at the same level with the same name, and if it is I'll venture to say it was boneheaded design.