number of requests a browser has to make to download a web page. By using Expires headers you can stop the
An additional benefit of using expires headers is they reduce the number of requests, allowing web pages to load
quicker and use less bandwidth. This can have additional benefits if your visitors have limited bandwidth (for
example accessing the site via a mobile)
For Apache the quickest way is to add the following to your .htaccess file.
ExpiresDefault "access plus 4 weeks"
This will send an expires header allowing the file to not be requested for 4 weeks for all files having the
extensions .gif, .png, .jpg, .css, .js, .swf, .flv and .ogg.
For the above to work you need to ensure that the Apache mod_expires is enabled. In debian/Ubuntu this can easily be
done by running
Any files with caching headers need to have a versioned filename, otherwise the changed files will not be
downloaded when they are updated until the expires date has passed