Hide The Extension Into Htaccess File

First you should delete the extension from your link.

<a href="blog.php">  you have to delete ".php" part.

<a href=blog>

Second, open your .htaccess file from root directory.

copy this code into it:

__________________________________________

#additional

RewriteEngine On

RewriteCond %{REQUEST_FILENAME} !-f

RewriteRule ^([^\.]+)$ $1.php [NC,L]

#additional

__________________________________________

That is so easy guys. Wish you luck ;)