How to set up rewrites for files without extensions?

Question

htaccess

Hello. Please tell me about rewrites.
In general, the site is simple in html. But I don't want the .html extension to be visible. That is, I want the content of the domain.ru/contacts.html file to
be shown when visiting the URL domain.ru/contacts . This is what it looks like RewriteEngine on RewriteCond %{REQUEST_FILENAME} !-d RewriteCond % {REQUEST_FILENAME} !-f RewriteRule ^(.*[^/])$ /$1.html [NC,L] But there is a problem: When requesting a non-existent page, for example domain.ru/contacts123 , the server tries to find domain.ru/contacts123 .html,
but there is no such file on the server, so it tries to find .html again, resulting in a circular redirect and the server gives a 500 error instead of a 404 response.
So how to set up rewrites in such a way that there are beautiful URLs like domain.ru/contacts (exactly without a slash at the end), but at the same time, when requesting a non-existent page, receive a 404 response code?
Otherwise, Yandex Webmaster does not like that non-existent pages give a 500 response instead of a 404.

Answer 1

RewriteCond %{REQUEST_URI} !^.+\.(html|htm)$
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^(.+[^/])$ /$1.html [NC,L]