LiteSpeed is a high-performance web server with page caching built in, designed as a faster replacement for Apache.
LiteSpeed Web Server is the software that receives requests from visitors' browsers and sends back your web pages. It does the same job as Apache or Nginx, but it was built for speed and for handling lots of visitors with fewer resources. It's made by LiteSpeed Technologies.
Its big advantage for site owners is that it can replace Apache without changes. It reads the same .htaccess files and configuration, so a site moved from an Apache host usually works straight away and often runs faster.
How LiteSpeed works
Apache traditionally uses a separate process or thread for each connection, which uses more memory as traffic grows. LiteSpeed is event-driven. A small number of processes handle thousands of connections at once, switching between them as data arrives. That keeps memory use low during traffic spikes and makes features like keep-alive cheap to run.
It also runs PHP through its own fast interface, called LSAPI, and supports modern protocols including HTTP/2 and HTTP/3.
LiteSpeed Cache (LSCache)
LiteSpeed has full-page caching built into the server. When a page is cached, LiteSpeed sends a saved copy straight away without running PHP or querying the database. That's much faster than a caching plugin that has to start PHP first, and it saves entry processes on shared hosting.
To control the cache, LiteSpeed provides free plugins for popular apps. The LiteSpeed Cache plugin for WordPress also handles image optimisation, CSS and JavaScript minification, object cache connections and CDN settings.
LiteSpeed vs Apache vs Nginx
- Apache: very compatible and supports .htaccess, but uses more memory under heavy load.
- Nginx: fast and efficient, but doesn't read .htaccess, so rules must be rewritten.
- LiteSpeed: efficient like Nginx and compatible with Apache's configuration, with caching built in.
There's also OpenLiteSpeed, a free open-source edition. It's popular on self-managed servers but has some differences from the commercial version, including more limited .htaccess support.
Common LiteSpeed questions and problems
- Using another cache plugin as well: running two page caches at once can cause stale pages. Use LSCache alone on LiteSpeed servers.
- Pages not updating: purge the cache after big changes, or check that logged-in users and carts are excluded.
- Checking you're on LiteSpeed: look for
server: LiteSpeedin your site's response headers.
Every AblePage plan runs on LiteSpeed with LSCache for WordPress, alongside NVMe storage and AMD EPYC processors. See the WordPress hosting page for details.