Try my version:

# Run Php without filename extension
RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}.php -f
RewriteRule ^(.*)$ $1.php

# Return 404 if original request is .php
RewriteCond %{THE_REQUEST} "^[^ ]* .*?\.php[? ].*$"
RewriteRule .* - [L,R=404]

You can use the following.

RewriteEngine On
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^([^\.]+)$ $1.php [NC,L]

Basically this says if the File in the URL can’t be found on the server then in the backend load it again using .php. This will basically make the server take a /file request and because there is no /file on the server it will load /file.php instead. The user wont see the switch over but can still load both ways.

Thanks for sharing..
Working fine.....

Very very thanks…
code working

How to add 404 error page when extension restricted .php and .html both

If you looking for complete solution with explanation then i will recommended to Read this:
How to Hide PHP Extenstion Step By Step

You will get your answer 100%.