New visitors to your web site will make several HTTP requests to download all your web site files. By add Far Future Expires header, you make those files cacheable. This avoids unnecessary HTTP requests on subsequent page views. Expires headers should be used on all components including scripts, stylesheets, and Flash components.

If you have access to httpd.conf, you can add

[FilesMatch "\.(ico|pdf|flv|jpg|jpeg|png|gif|js|css|swf)$"]
Header set Expires “Thu, 15 Apr 2010 20:00:00 GMT”
[/FilesMatch]

* Replace [ with < and ] with >

You can also add the above code if you can only access .htaccess.

Remember to change the date when it expired.

Your web site Yslow performance grade should improve.

Popularity: 3% [?]

Entity tags (ETags) are a mechanism to check for a newer version of a cached file. Removing the ETag reduces the size of the HTTP headers in both the response and subsequent requests.

If you have access to httpd.conf, you can add

FileETag None

Or if you can only access .htaccess only, you can add

Header unset ETag
FileETag None

Your web site Yslow performance grade should improve.

Popularity: 2% [?]