This Short Tutorial shows you you How to Modify your URLs Adding an html Suffix on a PHP Site Blog.
Apache mod_rewrite Need to be Enabled
Add this RewriteRule to .htaccess on Site Root
RewriteRule ^(.*).html$ $1.php [NC]
The if you are on Localhost Restart Apache
Make a test.php file containing:
Insert in your browser the URL:
Now your Apache mod_rewrite should Rewrite your URL to Call the test.php file and so you should be able to See your PHP Installation Settings on screen.
Then you will be Able to Modify your URLs Adding the html Suffix Keeping untouched your PHP Site Files…