If you're running Squid to cache your website, you can use an htaccess file to control what kind of files should be cached, and for how long.


First you should enable mod_expires, the Apache module that can control the Expire HTTP header in server responses:

$ a2enmod expires


Next create a .htaccess file in your web root, containing:

ExpiresActive On
ExpiresDefault "access plus 4 hours"
ExpiresByType application/javascript A900
ExpiresByType application/x-javascript A900
ExpiresByType text/javascript A900
ExpiresByType text/html A90
ExpiresByType text/xml A90
ExpiresByType text/css A900
ExpiresByType text/plain A62
ExpiresByType image/gif A14400
ExpiresByType image/jpg A14400
ExpiresByType image/jpeg A14400
ExpiresByType image/png A14400
ExpiresByType image/bmp A14400
ExpiresByType application/x-shockwave-flash A3600

And that's it! Play around a bit with the values to suit your needs.