How to move a Wordpress Site out of the document root without changing the site's URL

Introduction

You may want to move your WordPress installation to a subfolder and not have the folder name in the URL.

Procedure

1. Make the folder to move the site into.
2. Move the files and folders from the document root to the new folder.
3. Create a new .htaccess file in the document root.
4. Open the new .htaccess file in your preferred text editor.
5. Add the following to the .htaccess file.

   <IfModule mod_rewrite.c>
   RewriteEngine on
   RewriteCond %{HTTP_HOST} ^(www.)?$domain.tld$
   RewriteCond %{REQUEST_URI} !^/$newfolder/
   RewriteCond %{REQUEST_FILENAME} !-f
   RewriteCond %{REQUEST_FILENAME} !-d
   RewriteRule ^(.*)$ /$newfolder/$1
   RewriteCond %{HTTP_HOST} ^(www.)?$domain.tld$
   RewriteRule ^(/)?$ $newfolder/index.php [L] 
   </IfModule>

   Please note that "$domain.tld" and "$newfolder" must be replaced with your site's domain name and the new folder name, respectively.
6. Save the changes and exit the text editor.

Additional resources

File Manager