This page illustrates how you can redirect a page so that the file extension is no longer visible.
Try it out
The filename of the page you are looking at is
/examples/this-is-a-page.php
However, if you look at your browser's address bar, or if you click a link to this page, you will always see the extensionless version:
/examples/this-is-a-page
Read more
Read more about the advantages of removing file extensions and a simple way to do it in the blog post below.