Using Long Cache Headers to Increase Your Site Performance

One of the best ways to improve website loading performance is setting good cache headers. Web browsers, Internet Service Providers, and network operators use cache headers to decide whether or not data downloaded from the Internet should be saved for later use when accessing the same page or website. Websites send Cache-Control Headers with their web page data to instruct what data should be stored for later and for how long that data should be stored before checking for a newer version. A Cache-Control Header with a lifetime of 30 days, for example, says the data should only be saved for 30 days before it is discarded and has to be downloaded again.

For many types of data, such as CSS, JavaScript, and image files, setting a very long cache duration is useful. It is recommended to set a caching duration of longer than 30 days for these kinds of files to help make sure that web browsers, Internet Service Providers, and network operators save copies of these files for use over an extended period of time. These caching services use this data to significantly improve website loading performance for their users.

WordPress websites can use plugins to automatically set long Cache-Control Headers on their data. Cache-Control Headers can also be managed by experienced developers and system administrators by configuring the web server, such as Apache or NGINX, that is being used to serve the WordPress website.