Is there a reason why someone visiting your website should know or care about file extensions?

I guess no one should know whether a pdf is a pdf. Or even whether it's a .com or a .org domain - the browser should just strip all that confusing stuff away!

When you're serving someone an HTML file are you serving them the exact copy on your file system or do you ever use templates? Do you ever pull info from the database? If so, can you see why this is slightly different from directly serving a static pdf?

Also note that you'll often see a PDF generated on the fly with a long, difficult to parse URL.

Take up your second point with the W3 or whatever, to be honest if tlds weren't so important for phishing and whatnot it would probably be fine. I think some browsers have started doing that anyway. You overestimate how tech savvy the average user is, and by extension you overestimate how much the average user can keep track of all this complexity. Do you think most people have heard of .info or .xyz?

That's what mime-type headers are for. The URL should locate a resource, as the name suggests, not necessarily convey metadata about what the resource is.

The user presumably wants to know what kind of content they're going to receive from a given endpoint - foo.html, foo.pdf, foo.jpg, foo.mp3 and foo.avi suggest quite different experiences, and it's nice to include that hint in the URL (where it's visible on mouseover) rather than the user having to go in blind. I also like being able to reassure the user that they're receiving the same piece of content however they access a given resource, rather than the possibility of invisible content negotiation changing the site's behaviour.

Such hints can be unreliable at best and misleading at worst. There is nothing to guarantee that the file extension and the Content-Type header will agree, nor is there anything to guarantee that the file name in the URL will match the download file name in the Content-Disposition header.

Well, sure, but you can just... not do that? The <title> tag can be misleading because there's no guarantee that the title matches the content of the page - but the answer to that is to use good titles for your pages, not to avoid using the <title> tag.

My point is that it isn’t really reassuring for the user because of invisible negotiations. If anything, I would lean more towards guessing that users are, more often than not, either ignorant or untrusting of URL contents, either because the URLs so frequently look like nonsense (arbitrary content IDs instead of meaningful names) or because they have already proven to be unreliable elsewhere on the web (deep links not as deep as expected when copied or shared).

> If anything, I would lean more towards guessing that users are, more often than not, either ignorant or untrusting of URL contents, either because the URLs so frequently look like nonsense (arbitrary content IDs instead of meaningful names) or because they have already proven to be unreliable elsewhere on the web (deep links not as deep as expected when copied or shared).

I think users are (rightfully) distrustful of URLs in the general case, but a URL having a file extension is actually a pretty good indication that it's a simple "does what it says on the tin". (Imgur changing their .jpg URLs to have more complex behaviour caused a pretty big backlash, for example)

Maybe this is just me, but I like that I can decouple the way I organize my file system from the way users access my site. And with that comes the ability to get rid of file extensions and make urls more human-friendly. Remember, not every person has file extensions turned on by default on their Windows File Explorer!

It's just you.

Ok, I set myself up for that.

Do you have experience running websites that cater to the non tech savvy? How are your urls set up? Do they get confused where to find things? Do you use a database? Do you dynamically render content using templates?

Not the GP here, but having run websites for the non tech savvy I can say they have no problems with any sort of URL structure because they are oblivious to URLs. They enter your-site.com into Google, click the first result (even if that’s an ad for your competitor), and then click round the links presented.

My web server is not exposing file system paths to the user, it is deciding on content programmatically and it’s purely an aesthetic coincidence that the url path looks like a file system path.