Permanent redirect removal of file extensions in URL

Question

When a page is visited using a URL that ends with .html, I'd like the URL to change to having no extension and report 301 permanently redirected. I'm having serious difficulty. After reading a lot of documentation and tutorials, and searching Stack Overflow for hours, the closest I've achieved is the opposite (URLs with no extension having one added) with this code:

<Location />
    RewriteCond %{REQUEST_FILENAME} !-d
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteCond %{REQUEST_FILENAME}\.html -f
    RewriteCond %{REQUEST_URI} !/$
    RewriteCond %{REQUEST_URI} !\.html$
    RewriteRule ^(.*)$ https://%{HTTP:Host}%{REQUEST_URI}.html [L,R=permanent]
</Location>

Answer 1

This can be done in two steps, with a REDIRECT_LOOP environment variable to prevent looping, with the directives in a Directory section for the web root (or .htaccess in the web root) so the matched string in the RewriteRule can be used for the permanent Redirect.

<Directory "/var/www/html">

 RewriteEngine On

 RewriteCond %{REQUEST_FILENAME} !-d # if the request is not a directory
 RewriteCond %{REQUEST_FILENAME} !-f # if the request is not a file
 RewriteCond %{REQUEST_FILENAME}\.html -f # if adding .html it is a file
 RewriteCond %{REQUEST_URI} !\.html$ # if the request doesn't end in .html
 RewriteCond %{REQUEST_URI} !/$ # if the request doesn't end in /
 RewriteRule ^(.*)$ $1.html [L,E=LOOP:1] # then return the request as if it ended with .html and set the loop variable

 RewriteCond %{ENV:REDIRECT_LOOP} !1 # if we didn't just added .html
 RewriteRule ^(.*)\.html$ https://%{HTTP:Host}/$1 [L,R=permanent] # then 301 redirect the request to the request without the .html

</Directory>

This will make it so that if you have example.html and example/index.html then example.html will never be loaded.