Installing WP Super Cache

WordPress is a popular tool that generally works very well to run your website.

However, once your site begins to receive a significant amount of traffic, you may notice that WordPress runs less efficiently. This is because whenever a page is visited, it must be processed by PHP and then served via the server which can consume vast amounts of memory if your site gets even a moderate traffic spike.

Caching plugins

Installing a cache plugin can help cut down on memory usage by serving cached static files instead of requiring each request to retrieve the same information from the server. This also helps your site survive large traffic spikes and keep it up and running in DreamHost's shared hosting environment.

View the WordPress caching options page for further details. This article explains how to set up WP Super Cache.

Configuring WordPress permalinks

WP Super Cache requires the use of permalinks.

When configuring permalinks within WordPress, you’ll notice several options available. Please note that all permalink settings work with WP Super Cache except for the default settings.

To change the default settings:

  1. Go to your WordPress dashboard (example.com/wp-admin).
    01 WP Super Cache.fw.png
  2. Navigate to ‘Settings -> Permalinks’.
    Any of the options aside from Default will work, so your settings should look something like this:
    02 WP Super Cache.fw.png
  3. Click the Save Changes button to save your new settings.

Setting up WP Super Cache

Before you install WP Super Cache

If you have previously installed any other caching plugin, you should deactivate and remove it. In general, double caching is a bad idea and can create conflicts that could slow down your WordPress site. Known plugins that conflict are WP Cache and W3 Total Cache.

Make sure you remove or disable them fully before installing WP Super Cache. This can be done from the WordPress Dashboard – click ‘Plugins’ on the left to view and edit your list of plugins.

Installing WP Super Cache

To install WP Super Cache:

  1. Download the WP Super Cache plugin via your WordPress Admin Dashboard at example.com/wp-admin.
    03 WP Super Cache.fw.png
  2. Once logged in, click ‘Plugins > Add New’.
  3. Towards the top right of the screen, search for WP Super Cache (or wp-super-cache).
    04 WP Super Cache.fw.png
  4. Click the Install Now button next to WP Super Cache.
  5. In the pop-up that dispalys, click the OK button to save your changes.
    This will install WP Super-Cache and allow you to immediately activate it.
    06 WP Super Cache.fw.png

Activating WP Super Cache

To activate the WP Super Cache plugin:

  • Click the 'Activate Plugin' link on the installing page (see previous section), or
  • Go to the Plugins area of your admin dashboard (Plugins -> Installed Plugins), and then click the 'Activate' link.
When you activate the WP Super Cache plugin, the following appears:
07 WP Super Cache.fw.png
  • Click the ‘Settings’ link to open the WP Super Cache configuration page.
From there, adjust your settings to look similar to the following:
08 WP Super Cache.fw.png

Click the radio button titled 'Caching On (Recommended). Then click the 'Update Status' button.

WP Super Cache automatically adds the following line to your wp-config.php file:

define( 'WP_CACHE', true );

If it fails to do so, WordPress provides links to its own troubleshooting documents.

Verifying WP Super Cache is actually working

To test WP Super Cache:

  1. Open the WP Super Cache admin page and click the 'Easy' tab.
    09 WP Super Cache.fw.png
  2. Click the Test Cache button which tests if WP Super Cache is functioning.
    The following appears when you click the Test Cache button:
    10 WP Super Cache.fw.png

Caching types

Click the 'Advanced' tab to view the different caching types. WP Super Cache supports two modes:

  • Simple
  • Expert (mod_rewrite)

You can change these in the ‘Advanced Settings’ tab:

11 WP Super Cache.fw.png

There are pros and cons to each option. However, in terms of performance or if your content is not going to change that often, you will most likely use 'Expert' (mod_rewrite) mode which speeds up the Time to First Byte (TTFB) by orders of magnitude. This is because it doesn't have to search for additional PHP handlers to parse the cached file. Instead, it writes the content as raw HTML, and then serves the HTML by itself.

If you're using NGINX, you'll want to use 'Simple' mode.

mod_rewrite mode

If you switch to using 'Expert' mode, mod_rewrite options appear further down on the page.

WP_Super_Cache_Mod_Rewrite

Under the 'Cache Location' section, step#5 appears.

Below that is a new section titled 'Mod Rewrite Rules'. As it says, you do not need to update the rules unless a warning displays in that location.

Page Speed Optimization with WP Super Cache

View the following article for further details on how to combine these two:

Making WP Super Cache work with Nginx

The following lines are just a snippet from a whole wordpress.conf file. You can find this on your Nginx server in the following directory:

  • /home/username/nginx/example.com/wordpress.conf
###### rest of wordpress.conf above...
###

# only rewrite to the supercache file if it actually exists
if (-f $document_root$supercache_file) {
  rewrite ^(.*)$ $supercache_file break;
}

### stats
if ($request_uri ~* ^/(stats|doc|failed_auth\.html).*$) {
  break;
}

# all other requests go to WordPress
if (!-e $request_filename) {
  rewrite ^.*$ /index.php last;
}

View the following article for further details

See also

Internal links

External links

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Article last updated .