Using the "WP Super Cache" WordPress plugin
WP Super Cache is a WordPress plugin that dramatically speeds up the performance of WordPress sites. Installing it is one of the steps we recommend for improving WordPress performance.
On this page:
- Activating WP Super Cache
- Configuring WP Super Cache
- Configuration tips
- Looking for even better performance?
- Ignore warnings about a “writable” directory
- Enabling WP Super Cache for a domain name alias
- What about W3 Total Cache?
Activating WP Super Cache
The plugin can be activated from within the WordPress “Dashboard” admin pages.
If you used our WordPress “one click installer”, the plugin is already part of your site and just needs activating:
- Click Plugins.
- Locate the line for the “WP Super Cache” plugin.
- Click Activate Plugin.
If you installed WordPress yourself (without using our installer), do this instead:
- Click Plugins.
- Click the Add New button.
- Search for the term WP Super Cache, then click Install Now when you find it. After installing it, you’ll be told that WordPress “Successfully installed the plugin”.
- Click Activate Plugin.
Configuring WP Super Cache
Activating the plugin speeds up your site somewhat, but you can speed things up even more by configuring it a little more. To do that:
- Click Settings on the left side of the WordPress Dashboard.
- Click WP Super Cache under the Settings.
- Click the Advanced tab to set the caching options.
It will look like there are lots of options, but actually, configuring it is easy: simply choose all the “recommended” options, and leave the others off. It should look like this (we’ve highlighted the recommended settings for you):
When you’ve set things that way, click “Update Status” to save the changes.
Finally, you may see a message saying “Rewrite rules must be updated. The rewrite rules required by this plugin have changed or are missing. Scroll down the Advanced Settings page and click the Update Mod_Rewrite Rules button.” If so, do that.
You’re finished!
If you prefer, we’ll be glad to install WP Super Cache for you, at no charge, on any copy of WordPress. Just contact us.
Configuration tips
If you get an error message when you activate WP Super Cache, saying that “Mod Rewrite rules cannot be updated” because of missing “BEGIN and END markers” in a .htaccess file, you can easily fix this. Choose Settings > Permalinks in the WordPress admin screens, make sure anything except “Default” is chosen, then Save Changes (even if you don’t actually make any changes). This creates the file (if necessary) and adds the correct markers. The WP Super Cache Manager should then be able to update the .htaccess file.
When you configure the WP Super Cache settings, do not check the box marked “Clear all cache files when a post or page is published”. Using that checkbox is effectively disables WP Super Cache for a few minutes every time you create a new post.
Looking for even better performance?
If you use FeedBurner to generate feeds for your site, you should make a small change to allow your feeds to be cached.
If you didn’t use our “one click installer”, we have two other tips (our installer already takes care of these):
First of all, if your site doesn’t display different content when search engine robots index it, and you care about how quickly Google and other search engines think your pages load (you should), you can remove “bot, ia_archive, slurp, crawl, spider, Yandex” from the “Rejected User Agents” section of the Advanced settings — just make that space blank. This helps search engines get the same speed benefits.
Finally, we recommend increasing the “Expire time” to 172800 seconds in the “Expiry Time & Garbage Collection” section of the Advanced settings for the reasons described here, even though it suggests setting it lower for a busy site.
Ignore warnings about a “writable” directory
Some versions of WP Super Cache may display a warning like this in the “Directly Cached Files” section of the plugin settings page:
Warning! /var/www/html/ex/example.com/ is writable. Please make it readonly after your page is generated as this is a security risk.
This warning is due to a bug in WP Super Cache that occurs when you haven’t configured “Directly Cached Files” (which you don’t need to do). You should ignore the warning.
Enabling WP Super Cache for a domain name alias
If you try enabling WP Super Cache using a URL that’s a domain name alias, four of the lines that WP Super Cache adds to your .htaccess file may be incorrect. This is caused by a WP Super Cache bug.
Specifically, if your .htaccess file contains “/var/www/html/ex/example.com” in the RewriteCond and RewriteRule lines that were added, that extra text is wrong and should be removed. We can help you troubleshoot and fix this problem if you contact us.
What about W3 Total Cache?
“W3 Total Cache” is a plugin that tries to do the same thing as WP Super Cache. However, we’ve found that it’s harder to use and sometimes doesn’t give the same performance. Stick with WP Super Cache unless you have a good reason to switch.