Using .htaccess to make all .html pages to run as .php files?

In My Godaddy Server the following code worked

Options +ExecCGI
AddType application/x-httpd-php .php .html
AddHandler x-httpd-php5 .php .html

This is in edition to all other right answers:

If you are not able to find the correct Handler, Simply create a .php file with the following contents:

<?php echo $_SERVER['REDIRECT_HANDLER']; ?>

and run/open this file in browser.

Use this output in .htaccess file

Create a .htaccess file at the root of your website(usually a folder named public_html or htdocs on linux servers) and add this line:

AddType [[THE OUTPUT FROM ABOVE FILE]] .html .htm

Example

AddType application/x-httpd-php70 .html .htm

Important Note:

If you see blank page or Notice: Undefined index: REDIRECT_HANDLER

Try default in .htaccess

AddHandler application/x-httpd-php .html

You may also use the H or T flag of mod_rewrite to force all .html files to be parsed by php handler :

using H (Handler) flag:

 RewriteEngine on

RewriteRule \.(html|htm)$ - [H=application/x-httpd-php5]

using T (Type) flag :

 RewriteEngine on

RewriteRule \.(html|htm)$ - [T=application/x-httpd-php5]

Or you can add more extensions to the rule pattern seprated by a pipe | that you want to be parsed by php handler

ex :

RewriteRule \.(html|htm|txt|foo)$ - [T=application/x-httpd-php5]

the example above will change the mime type of files that end with .html , .htm , .txt , .foo to php.

Note : on some servers you will have to change php5 to php to get this example to work in handler string:

Change it

[T=application/x-httpd-php5]

to

[T=application/x-httpd-php]

You need to add the following line into your Apache config file:

AddType application/x-httpd-php .htm .html

You also need two other things:

1. Allow Overridding

   In your_site.conf file (e.g. under /etc/apache2/mods-available in my case), add the following lines:

   <Directory "<path_to_your_html_dir(in my case: /var/www/html)>">
       AllowOverride All
   </Directory>
   

2. Enable Rewrite Mod

   Run this command on your machine:

   sudo a2enmod rewrite 
   

   After any of those steps, you should restart apache:

   sudo service apache2 restart
   

For anyone out there still having trouble,

try this (my hosting was from Godaddy and this is the only thing that worked for me among all the answers out there.

AddHandler x-httpd-php5-cgi .html

Running .html files as php stopped working all of a sudden in my .htaccess file.

Godaddy support had me change it to:

AddHandler application/x-httpd-lsphp .html

I think this is the best way to run php script on html and htm pages:

AddType application/x-httpd-php5 .html .htm

Normally you should add:

Options +ExecCGI
 AddType application/x-httpd-php .php .html
 AddHandler x-httpd-php5 .php .html

However for GoDaddy shared hosting (php-cgi), you need to add also these lines:

AddHandler fcgid-script .html
FCGIWrapper /usr/local/cpanel/cgi-sys/php5 .html

Source: Parse HTML As PHP Using HTACCESS File On Godaddy.

here put this in your .htaccess

AddType application/x-httpd-php .php .htm .html

more info on this page

Using @Marc-François approach Firefox prompted me to download the html file

Finally the following is working for me (using both):

AddType application/x-httpd-php .htm .html AddHandler x-httpd-php .htm .html

AddHandler application/x-httpd-php .php .html .htm
// or
AddType application/x-httpd-php .php .htm .html

I'm using PHP7.1 running in my Raspberry Pi 3.

In the file /etc/apache2/mods-enabled/php7.1.conf I added at the end:

AddType application/x-httpd-php .html .htm .png .jpg .gif

On Dreamhost Servers you can refer to this page that at time of writing indicates you may use the following for php 7.2 with FastCGI:

AddHandler fcgid-script .html
FcgidWrapper "/dh/cgi-system/php72.cgi" .html

Or if you are using php5 cgi (not FastCGI):

AddHandler php5-cgi .html

None of the answers posted here worked for me.

In my case the problem was, by the one hand, that the .conf file (/etc/apache2/sites-available/default-ssl.conf or /etc/apache2/sites-available/000-default.conf) did not contain the directive AllowOverride All for the site directory, which caused the .htaccess to not been processed. To solve this, add:

<Directory /var/www/html/>
        Options Indexes FollowSymLinks
        AllowOverride All
        Require all granted
</Directory>

On the other hand, the problem was that the .htaccess was created by the root user, and therefore the apache user could not read it. So, changing the file owner solved definitely the problem:

chown www-data:www-data .htaccess

First, read this: https://httpd.apache.org/docs/current/howto/htaccess.html#when

Then read my post here: https://stackoverflow.com/a/59868481/10664600

sudo vim /etc/httpd/conf/httpd.conf

Sometimes it doesn't work, if you just add the .htaccess file to the directory. In my case, I also changed an entry in the apache2 configuration.

sudo nano /etc/apache2/apache2.conf

...

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride None
    Require all granted
</Directory>

Modification:

<Directory /var/www/>
    Options Indexes FollowSymLinks
    AllowOverride All
    Require all granted
</Directory>

After that you only must restart the apache2-service:

sudo systemctl restart apache2

This worked for me.

This would help anyone,

RewriteEngine on
RewriteRule ^(.+)\.html$ $1.php [L]

Digitalocean

Thanks @FlamberHansen.

If you're on Plesk running PHP as an FPM application served by Apache this article worked for me:

Go to Domains > example.com > PHP Settings and add the following lines into the field Additional configuration directives:

[php-fpm-pool-settings]
security.limit_extensions = .php .phar .html .inc

.htaccess

<Files ~ .(?i:inc|html|htm)$>
SetHandler proxy:unix:///var/www/vhosts/system/EXAMPLE.com/php-fpm.sock|fcgi://127.0.0.1:9000
</Files>