Probably a question for the Apache forum.

I would say that there is no advantage to showing an extension - neither search engines nor users care, and if you ever change from PHP to something else it will be extra work.

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Thanks for your reply. Will note the Apache forum for next time.

If you must add an extension, add one which indicates the content of the file not the technology which generated it. Therefore, an HTML file could usefully end in .html, but gains nothing by ending in .php. Then again - HTML may not be the language of choice for webpages in the future - so play it safe and put nothing there as an extension.

Personally - I like to customise the extension to the site - perhaps a site about Widgets would have pages ending in .widget... probably SEO benefit as well as a chance for added branding.

Classic link: Cool URI's don't change [w3.org]

I believe the general consensus today is to get away from any extensions. And this is what I have seen many websites do.

But...

Personally I think this is very wrong, and my experience is that if your page generates html, give it an .html ending...

I also have non-conclusive evidence that this actually helps your SEO ranking with Google these days. And not just marginally, but by a good percentage.

There is also the benefit of not confusing anyone or anything [spiders,bots,crawlers] of whether URL /cat/sub[/] is a page or a folder. Most of them will try to add an ending '/' to see if they can get into it deeper. And if you do not have the proper mod_rewrite rules set, you are going to have duplicate content. Yes, Google is smart enough to figure it out, but you will still get penalized a bit.

Thanks Tower - interesting points