LiteSpeed Cache is a free caching plugin that outperforms most alternatives when a site runs on a LiteSpeed or OpenLiteSpeed web server. Here is how to set it up and how it differs from a Redis-based cache.
What LiteSpeed Cache is and when it runs faster
LiteSpeed Cache is a plugin that serves a cached page right at the web server level, before PHP and WordPress even start. This type of cache is called server-side: it saves time not only on running PHP code but on launching the WordPress engine itself. There is one condition for this speed — the site must run on a LiteSpeed or OpenLiteSpeed web server, not Apache or Nginx.
If the site does not run on LiteSpeed, the plugin can still be used — it can work as a regular PHP-level cache, but then part of the speed advantage is lost.
Installing and configuring the plugin
Install the LiteSpeed Cache plugin from the WordPress directory and enable caching in the Cache → Settings section. The minimum set of settings to start with:
- Enable Cache — turn on the main page cache.
- Cache Mobile — a separate cache for the mobile version, when the theme is not fully responsive.
- TTL Public Cache — cache lifetime, typically 604800 seconds (7 days).
- Private Cache for pages accessed by logged-in users.
After enabling the cache, check the home page — the HTML source should show a comment like Page generated by LiteSpeed Cache right before the closing </html> tag.
Image optimization and minification
The Image Optimization tab sends images to the QUIC.cloud service for compression with no noticeable quality loss and conversion to WebP. Run optimization for the whole media library like this:
# Run image optimization through WP-CLI (if the LiteSpeed CLI module is installed)
wp litespeed-media optimize --all
In the Page Optimization tab, enable CSS and JS minification and file combining — this reduces the number of requests to the server on first page load. Turn these options on one at a time and check the layout: aggressive minification sometimes breaks inline scripts in themes and page builders.
LiteSpeed Cache versus Redis: which to choose
LiteSpeed Cache caches the entire rendered HTML page, while Redis is an object cache inside PHP that speeds up database queries but does not remove the time spent rendering the page. Comparison by task:
| Task | LiteSpeed Cache | Redis |
|---|---|---|
| Serving a static blog page | Maximum speed, the page is served without PHP | Faster than no cache, but slower than LiteSpeed |
| Dynamic WooCommerce store | Some pages cannot be cached in full (cart, account) | Speeds up database queries on non-cacheable pages |
| Server requirements | Requires a LiteSpeed or OpenLiteSpeed web server | Requires the PHP Redis module and a Redis service on the server |
For WooCommerce stores, it is worth combining both: LiteSpeed Cache for catalog pages and Redis for the object cache of the cart and account; object cache setup is described in the article Redis Cache for WordPress: 5-10x Speedup.
Checking the result after setup
After configuring the cache, measure page load speed before and after with a site speed testing tool. Pay attention to the Time to First Byte metric — it shows the effect of a server-side cache most clearly. If the site still loads slowly, check the other speed methods in the article WordPress Speed: 10 Ways to Speed Up a Site.
Also check the database: cluttered revision and transient tables slow down even a cached site every time a new cache page is generated — clean them up using the instructions in the article WordPress Database Optimization: Speed and Cleanliness.
LiteSpeed Cache setup checklist
- The site's web server is LiteSpeed or OpenLiteSpeed, so caching runs at the server level.
- Enable Cache and TTL Public Cache are configured in the Cache tab.
- Images are optimized and converted to WebP.
- CSS and JS minification has been checked on real pages of the site.
- A Redis object cache is added for WooCommerce's non-cacheable pages.