Set HTTP Caching Expiration, Recommended by Google PageSpeed

Question

I ran tests on my website using Google's PageSpeed and it recommends that I "Leverage browser caching" and provided the following resource:

http://code.google.com/speed/page-speed/docs/caching.html#LeverageBrowserCaching

This resource never explains how to actually change the expiration date of my http headers. Do I do this through .htaccess? I would like to set the caching for as long as possible (without violating Google's policy of a year max).

Any advice on recommended settings (for a custom php-driven social networking community) would be greatly appreciated.

Answer 1

In your root's .htaccess:

<IfModule mod_expires.c>
  ExpiresActive On
  ExpiresDefault "access plus 1 seconds"
  ExpiresByType image/x-icon "access plus 2592000 seconds"
  ExpiresByType image/jpeg "access plus 2592000 seconds"
  ExpiresByType image/png "access plus 2592000 seconds"
  ExpiresByType image/gif "access plus 2592000 seconds"
  ExpiresByType application/x-shockwave-flash "access plus 2592000 seconds"
  ExpiresByType text/css "access plus 604800 seconds"
  ExpiresByType text/javascript "access plus 216000 seconds"
  ExpiresByType application/x-javascript "access plus 216000 seconds"
  ExpiresByType text/html "access plus 600 seconds"
  ExpiresByType application/xhtml+xml "access plus 600 seconds"
</IfModule>

And follow by:

<IfModule mod_headers.c>
<FilesMatch "\\.(ico|jpe?g|png|gif|swf)$">
Header set Cache-Control "max-age=2692000, public"
</FilesMatch>
<FilesMatch "\\.(css)$">
Header set Cache-Control "max-age=2692000, public"
</FilesMatch>
<FilesMatch "\\.(js)$">
Header set Cache-Control "max-age=216000, private"
</FilesMatch>
<FilesMatch "\\.(x?html?|php)$">
Header set Cache-Control "max-age=600, private, must-revalidate"
</FilesMatch>
Header unset ETag
Header unset Last-Modified
</IfModule>

This is the exact same code I use on every property I manage and offers me (and PageSpeed) the most satisfying results. One may argue on specific rules, that's why I said that it satisfies me, but it certainly satisfies PageSpeed.