Password Protecting Individual Files
It's possible to create a .htaccess file so that individual files are protected instead of protecting a whole directory (folder).
However, you should only attempt this if you are an advanced user and familiar with .htaccess files and the syntax they use. Unless there is a specific reason why you need to protect a single file, we wouldn't normally recommend it. In our experience, creating a separate folder for sensitive files is a far simpler and less error-prone.
If you do decide to protect an individual file, you can do so by adding a FilesMatch directive to a .htaccess file. For instance, the following code will protect the file called secrets.html:
<FilesMatch secrets.htm> AuthName "Restricted File" AuthType Basic AuthUserFile /home/ex/example.com/webpasswords-passwordlist require valid-user </FilesMatch>
As with all .htaccess files, the rules will also be applied to any subdirectories unless they are overridden by additional .htaccess files.
