Favorite WordPress Plugins: WP Super Cache

There’s a few WordPress plugins that I just can’t live without. I like (and need) them so much that I’ve contributed to the plugin author to encourage them to keep developing the plugin. There’s only a few of these and the first I’ll write about is WP Super Cache. As the name implies it’s a caching plugin for WordPress. The plugin setup may be a little more complicated than other plugins you’ve installed. This depends on the security settings of your webhost. The included readme, along with the website does an excellent job of explaining the installation process so I won’t repeat it here. I will mention that the administration page for WP Super Cache will report on problems it’s found and offer suggestions for resolution. For example, if it can’t write to the .htaccess file it will tell you so.

I still have an account with Bluehost so I went in and was enable to activate the plugin entirely through the WordPress admin panel, I didn’t need to change any file permissions or create directories myself. The .htaccess file could also be modified by the plugin. (of course, there are those of us who’d prefer the web server didn’t have the access necessary to do such things, but that’s another story.) So it was no more difficult that a regular plugin.

WP Super Cache is based on the WP-Cache plugin and has a “half on” mode where it duplicates the functionality of the legacy WP-Cache plugin. This may avoid conflicts with some plugins or other blog features.

One potential caveat is that if your WordPress site has a lot of dynamic data this won’t be updated very often as it will be served on the cached pages. I use it on this site. While I’ve used it with compression enabled and haven’t had any problems I’ve since switched to using mod_deflate and have disabled compression in the plugin. But using a tool to test compression reported compression in excess of 70% for pages on this site when I had it enabled.

There was also a noticeable improvement in performance when I browsed to cached pages. This site only gets about 325 page views a day so the server isn’t under a lot of stress but there was a noticeable drop in memory and cpu usage once I implemented caching. CPU usage seemed to increase a bit again when I turned on compression through the plugin but cpu usage has never been a problem with this site.

Cached pages aren’t served to logged on users or those who left comments so if your site is mostly registered users or commenters then caching may not be for you, but it’s a big help for the rest of us.