How to add image cache headers? When doing SEO tests, we consistently seeing a message for cache headers on images. We were thinking of implementing but cannot find the appropriate way to test this as the x-cache still gives a MISS. 

Below is the htaccess file we have to accommodate for adding cache header for images.

How can I test to see the performance gain if I did this? 

# One month
&lt;filesMatch ".(css|jpg|jpeg|png|gif|js|ico)$"&gt;
  Header set Cache-Control "max-age=2628000, public"
&lt;/filesMatch&gt;
Currenty working on that. The code

# One month
 &lt;filesMatch ".(css|jpg|jpeg|png|gif|js|ico)$"&gt;
  Header set Cache-Control "max-age=2628000, public"
 &lt;/filesMatch&gt;


helped me to remove images from the list below https://developers.google.com/speed/