Main Features

Event-driven architecture with extremely low resource (CPU and RAM) overhead
Handles hundreds of thousands of concurrent connections without load spikes
High-performance coding using kqueue (FreeBSD and OS X), epoll (Linux), /dev/poll (Solaris), and poll
Worker processes for scalability. Ability to bind certain processes to particular workers
WebAdmin GUI with build-in real-time statistics graphical dashboard
Rewrite engine uses Apache mod_rewrite syntax
Support of third-party modules through API (LSIAPI)

Performance Features

Reduce Bandwidth Usage

  • Sendfile() support
  • Gzip compression
  • Brotli compression for static files

Even Faster Technologies

  • HTTP/3 and QUIC
  • All version of SPDY/2, 3, 3.1 and HTTP/2 support
  • Pipelined requests
  • TCP_FASTOPEN support
  • HTTP/2 Server Push

External Applications Support

  • Supports PHP, Ruby, Python, Perl, and Java external applications
  • LSAPI, a LiteSpeed-native SAPI, greatly improves PHP, Ruby, and Python speeds
  • Prometheus Exporter allows data to export from LiteSpeed Web Servers for use with Prometheus, Grafana, and similar analytics apps
  • Delegates external applications to separate processes, increasing efficiency
  • Buffers requests and responses to external applications to more efficiently serve multiple connections
  • Efficient CGI daemon
  • Compatibility with third party PHP accelerators
  • More efficient communications, controlled number of processes, and less web server resource usage increases scalability of web applications

Security Features

SSL Support

  • Apache-compatible SSI support
  • SSL support and hardware acceleration
  • TLS 1.0, 1.1, 1.2, 1.3
  • Anti SSL BEAST and renegotiation attack capabilities
  • libressl support

Security Controls

  • Bandwidth and connection throttling
  • IP-based access control
  • Strict HTTP request validation
  • Referer limiting
  • Response rate limiting

Server Alert

  • Buffer overrun guards

Stability Features

  • Graceful restart feature allows application of configuration changes and upgrades without server downtime
  • Fault tolerance and instant restarting
  • Runs completely in user space. OS reliability is not affected

Basic HTTP Server Features

Unlimited concurrent connections
Accept-filters and TCP_DEFER_ACCEPT support
Chunked transfer encoding
Keep-alive connections
IPv4 and IPv6
Entity tags
Multi-range requests
Exact/prefix/regex-based matching
Unlimited name-based and IP-based virtual hosting
Custom error pages
Set Cache‑Control headers

Advanced Features

  • Easy virtual host configuration via templates
  • Easily run multiple versions of PHP on one server
  • Build-in tool for compile PHP module
  • Can send logging to logging server
  • XML or flat file configuration
  • Smart server push
  • OCSP stapling

Advanced Modules

  • PageSpeed Module support
  • GeoIP modules to locate users by IP address (requires MaxMind GeoIP database)

As Load Balancer

  • Support HTTP/HTTPS
  • Build-in Round Robin Policy

As Proxy

  • WebSocket proxy support

As Reverse

  • Accelerate static content delivery, compress throughput
  • Proxying With Context / Rewrite Rules / Script Handlers


  • Lua scripting language

Streaming Media

  • VOD: Flash (flv), MP4