at which extensions caches the browser a page

Question

We have a web application.
Until now we had no real cache handling strategy.
When we had a new version of certain JavaScript files, we instructed our users to clear their browser cache.
Now we want to change this.
Up to this date our starting page was "start_app.html".
In our effort to implement our cache busting strategy we want to ensure that the browser will NOT cache our starting page.
We will change the extension from ".html" into ".php".
It seems that the browser has an array of extensions, when he ALWAYS fetches a fresh copy from the web server, like "php", "asp", and so on.
Is this true and which extensions are these?
Thanks alot in advance

Answer 1

Please don't rely on incorrect browser behavior to not cache your page. Instead, use this header:

Cache-Control: no-cache, no-store

This page has all the details as to why that header will do what you want.