FAQ¶

Here are some of our most Frequently Asked Questions.

Why do the cache features require a LiteSpeed Server?¶

This plugin communicates with your LiteSpeed Web Server and its built-in page cache (LSCache) to deliver superior performance to your WordPress site. The plugin’s cache features indicate to the server that a page is cacheable and for how long, or they notify the server to purge particular cached pages using tags.

LSCache is a server-level cache, so it’s faster than PHP-level caches. Compare with other PHP-based caches.

LSCache is a page cache. A page cache allows the server to bypass PHP and database queries altogether. LSCache in particular, uses its server connection to remember things about the cache entries and to analyze dependencies. It uses tags to manage the smart purging of the cache, and it uses vary cookies to serve multiple versions of cached content based on criteria like device type, geographic location, and currency. These things are harder for non-server-based cache plugins to achieve, if they can do them at all. See our Caching 101 blog series, if you want to learn more about this.

If the LSCache plugin's capabilities sound complicated, no need to worry. LSCWP works right out of the box with default settings that are appropriate for most sites. See the Beginner’s Guide to learn how to get started quickly.

What about the optimization features of LSCache?¶

LSCWP includes additional optimization features, such as Database Optimization, Minification and Combination of CSS and JS files, CDN Support, Browser Cache, Object Cache, Lazy Load for Images, Image Optimization, and more! These features do not require the use of a LiteSpeed web server.

Is the LiteSpeed Cache plugin free?¶

Yes, this LSCache plugin will always be free and open source. That said, a LiteSpeed server is required, and there are fees associated with some LiteSpeed server editions. Additionally, some of the premium online services provided through QUIC.cloud (CDN Service, Image Optimization, Critical CSS, Unique CSS, Low-Quality Image Placeholder, etc.) require payment at certain usage levels. You can learn more about what these services cost, and what levels of service are free, on your QUIC.cloud dashboard.

What server software is required for this plugin?¶

A LiteSpeed server is required in order to use this plugin. You will need one of the following (any single server or cluster including one of these will work):

• LiteSpeed Web Server Enterprise with LSCache Module (v5.0.10+)
• LiteSpeed WebADC (v2.0+)
• OpenLiteSpeed (v1.4.17+)
• QUIC.cloud CDN

Many of the optimization features may be used with any web server. A LiteSpeed server is not required for such features.

What is the difference between the LSCache Module for LiteSpeed Web Server (requires a license) and the LSCache plugin (free)?¶

The LSCache Module is built into your licensed copy of LiteSpeed Web Server. When it comes to caching dynamic content, the LSCache Module does all of the work.

The LSCache plugin is simply an interface. It allows the web app to instruct the server Module on what to cache, how long to cache it, and when to purge. And it allows the site owner to manage and configure the Module. Without the Module, the Plugin could not function.

A licensed LSCache Module is required in order to use the free LSCache plugin.

Does this plugin work in a clustered environment?¶

Yes. When using the plugin in a clustered environment, the cache entries are stored at the highest LiteSpeed server level. So, if you are using LiteSpeed's own Web ADC, then the cache can be stored at the ADC level. If you are using a third party load balancer, then the cache entries will only be stored at the backend LiteSpeed nodes, and cache purges will not be synchronized across the nodes.

We do not recommend a third party load balancing solution, if you wish to take advantage of LiteSpeed Cache, and keep cache entries synced between nodes.

Learn more about LiteSpeed Web ADC, or contact LiteSpeed Technologies via email for a customized solution.

Where are the cached files stored?¶

The actual cached pages are stored and managed by LiteSpeed Servers.

Nothing is stored within the WordPress file structure.

Does LiteSpeed Cache for WordPress work with OpenLiteSpeed?¶

Yes it can work well with OpenLiteSpeed, although some features (such as ESI) may not be supported. Any setting changes that require modifying the .htaccess file will require a server restart.

Is WooCommerce supported?¶

In short, yes. However, for some WooCommerce themes, the cart may not be updated correctly. Please see this blog post for a quick tutorial on how to detect this problem and fix it if necessary.

My site has some pages that are not cacheable. How do I instruct the LiteSpeed Cache Plugin to not cache the page?¶

From the WordPress Dashboard, navigate to LiteSpeed Cache > Cache > Excludes and add the necessary pages to Do Not Cache URIs.

How do I purge a single page from cache?¶

When you edit a page, the LiteSpeed Cache for WordPress plugin will automatically purge that page from cache, along with related pages like category, tag, and date archives. Still, there may be occasions where you would like to manually purge a single page. In this case, you would use the Purge this page - LSCache option on the Admin Bar. Please see Purge a Single Page From Cache for further instructions.

Are my images optimized?¶

Images are not optimized automatically unless you set LiteSpeed Cache > Image Optimization > Image Optimization Settings > Auto Request Cron to ON. You may also optimize your images manually. Learn more.

How do I make a WP nonce cacheable in my third-party plugin?¶

Our API includes a function that uses ESI to "punch a hole" in a cached page for a nonce. This allows the nonce to be cached for 12 hours, regardless of the TTL of the page it is on. Learn more in the API documentation.

How do I enable the crawler?¶

The crawler is disabled by default, and must be enabled by the server admin first.

Once the crawler is enabled on the server side, navigate to LiteSpeed Cache > Crawler > General Settings and set Crawler to ON.

For more detailed information about crawler setup, please see the Crawler documentation.

How can I install the LiteSpeed Cache Plugin?¶

The LiteSpeed Cache plugin works right out of the box with default settings that are appropriate for most sites. Please refer to the installation instructions to learn how to get started.

How do I know if LSCache is Working?¶

You can verify that LiteSpeed Cache is working by using the browser's developer tools, as described in Verify Your Site is Being Cached.