Basic Features

HTTP 1.0/1.1
LiteSpeed Web Server is an HTTP 1.1 server with HTTP 1.0 backwards compatibility. Notable HTTP 1.1 features include chunked transfer encoding, basic and digest authentication, entity tags, and range/multi-range request compatibility.
Scripting languages
LiteSpeed Web Server supports dynamic content written in PHP, Perl, Ruby, Python, and Java. These web applications are run as external engines. Communication between the applications is facilitated through the use of a number of server APIs (SAPIs), including LiteSpeed's exclusive LSAPI.
Server APIs
LiteSpeed Web Server supports a number of server APIs (SAPIs) for communication between the web server and external applications. The best performing and most efficient of these is LiteSpeed's exclusive LiteSpeed SAPI (LSAPI), which can be used for PHP, Ruby, and Python external applications. LiteSpeed also supports CGI, FCGI (for PHP, Ruby, Python, and Perl applications), AJPv13 (for Java applications), and proxy functions.
HTTPS
LiteSpeed Web Server supports SSLv3, TLSv1.1, and TLSv1.2. In addition, LiteSpeed can be easily configured to use SNI and OCSP stapling and to adhere to PCI compliance.
IPv4 and IPv6
LiteSpeed Web Server supports both IPv4 and IPv6.
Virtual hosting
LiteSpeed Web Server allows unlimited IP- and name-based virtual hosts. LSWS Standard Edition has a limit of five virtual hosts from Apache configuration files.
Concurrent connections
LiteSpeed Web Server licenses 1-CPU and above allow unlimited concurrent connections. The Ultra VPS license has a limit of 800 concurrent connections, while the VPS license has a limit of 500 concurrent connections. LSWS Standard Edition has a limit of 150 concurrent connections. OpenLiteSpeed has no limit on concurrent connections.
gzip compression
LiteSpeed Web Server's gzip compression feature allows you to save bandwidth by compressing the files sent to the client.
SPDY support
LiteSpeed Web Server supports SPDY versions 2, 3, and 3.1, and will support any new versions almost as soon as they come out.
WebSocket proxying
LiteSpeed Web Server’s WebSocket proxy feature allows you to use the ground-breaking realtime technology while controlling WebSocket connections with LiteSpeed’s performance and security features and using LSWS to serve other kinds of content on the same page.
Operating systems
LiteSpeed Web Server runs on Linux, FreeBSD, Mac OSX, and Solaris.

Apache Compatibility

Apache configuration files
LiteSpeed Web Server has been designed to run off Apache's httpd.conf and .htaccess files. There is no re-configuration necessary when you switch to LiteSpeed. LiteSpeed Web Server uses the settings you already have, but processes them with its event-driven architecture.
Control panels
LiteSpeed Web Server works seamlessly with all control panels written for Apache. With our plugins for cPanel, Plesk, and DirectAdmin plus the plugin Interworx has developed, it is even easier to drop LSWS into your server. These plugins/extensions allow you to control many common web server functions — such as installing LSWS — directly from the panel.
Full .htaccess support
LiteSpeed Web Server reads .htaccess files automatically, but processes them using .htaccess caching. Caching .htaccess files means that LSWS does not suffer the performance drop .htaccess files cause for Apache.
Apache modules
LiteSpeed Web Server is compatible with all Apache core modules, including mod_rewrite, mod_security, mod_include, and mod_cache.

Performance & Scalability

Event-driven architecture
The biggest difference between LiteSpeed Web Server and Apache is in the design of their architecture. Apache is process-based — it creates a new process or thread for every connection. Creating these processes requires a lot of overhead. LiteSpeed Web Server is event-driven, which means it serves all connections on a few processes, saving resources. This efficient method of serving connections means you can serve many more connections, at a much higher rate, without upgrading your hardware.
Concurrent connections
LiteSpeed Web Server's efficient event-driven architecture makes it possible for servers to serve hundreds of thousands of concurrent connections. Apache, by comparison, would run out of RAM long before it could serve so many concurrent connections.
Tiny memory footprint
LiteSpeed Web Server's event-driven architecture means it uses far less memory than Apache, leaving more hardware resources for other processes (like web applications and MySQL), and resulting in a faster, more stable server.
Sendfile()
Sendfile() is a "zero copy" system call that can greatly reduce CPU utilization when serving very large static files.
Asynchronous I/O
Asynchronous I/O is a form of input/output processing that permits other processing to begin before a transmission has finished, cutting latency. Only Enterprise Edition supports asynchronous I/O.
LiteSpeed server API (LSAPI)
LiteSpeed's exclusive server API can be used with PHP, Ruby, and Python external applications. Its optimized coding, extra features, and native use of LiteSpeed's configurations give LiteSpeed Web Server up to 40x better performance for these web applications — better than Apache, better than Nginx.
Shared hosting PHP
LSAPI's suEXEC daemon mode is designed specifically to speed up PHP web applications in shared hosting. In suEXEC daemon mode, PHP processes are started by using a fork() system call, instead of starting a brand new PHP process. This is much faster and allows users to effectively utilize opcode caching, while preserving the separation necessary for shared hosting.
suEXEC for different needs
LiteSpeed Web Server offers three different PHP suEXEC setups for different shared hosting needs. suEXEC Worker is for hosts with limited resources who need flexibility to customize. suEXEC Daemon mode combines blazing speed with light resource usage. suEXEC ProcessGroup allows hosts with extra resources to get even better performance through per-user opcode caching.
High-performance static content
LiteSpeed Web Server's event-driven architecture allows it to handle static requests much faster than Apache — up to 10x faster at high traffic volumes.
High-performance dynamic content
LiteSpeed's exclusive server API, LSAPI, handles web applications much more efficiently than other APIs, resulting in PHP, Ruby, and Python web applications that run up to 50% faster than with Apache.
SSL acceleration
LiteSpeed Web Server uses SSL acceleration to deliver HTTPS pages up to three times faster than Apache.
OCSP stapling
OCSP stapling speeds up the SSL verification process by attaching a pre-approved certificate to the SSL handshake response. This streamlines the process and removes burdens from the client and SSL certification authorities.
LSCache
LiteSpeed Web Server Enterprise licenses over 2-CPUs have LiteSpeed Cache. LSCache is full-featured caching software comparable to Varnish, but built into the software and customizable through rewrite rules, allowing for streamlined processes with supreme flexibility.
ESI support
Edge Side Includes allows you to break a page of dynamic content up into sections which can be served differently, giving you more detailed control over cache use. This allows for far greater cache use (and thus much faster service) with many web applications (like Magento and WordPress).
.htaccess caching
Using .htaccess files with Apache causes decreased performance, as Apache has to check every directory for .htaccess files. LiteSpeed Web Server uses .htaccess caching to make use of .htaccess files without the performance hit.
CloudLinux LVE compatibility
LiteSpeed Technologies enjoys a close partnership with CloudLinux, allowing for complete compatibility with this industry-leading shared hosting operating system.
Increases scalability of web applications
LiteSpeed Web Server's event-based architecture shrinks the amount of memory used by the web server software, especially at high traffic, leaving more RAM for web applications. LSAPI, LiteSpeed's exclusive server API, allows for faster application responses and request/response buffering means the server handles multiple connections to web applications more smoothly. All of this adds up to web applications that can serve more requests and scale larger on your current hardware.
Web application buffering
Instead of processing dynamic content as part of the server processes, LiteSpeed Web Server delegates requests for dynamic content to external web application processes. This frees up the server software to handle other requests while the external application is generating dynamic content. LSWS also buffers all requests and responses for or from the external applications so that external applications are not beholden to the speed of the client — the external application transfers the contents of the response to LSWS and then can start working on the next request without waiting for the client to receive the response over the network. These features mean web applications that run more smoothly in high traffic.
Just in time configuration
With just in time configuration, instead of parsing all Apache virtual host configurations at startup, the web server parses virtual host configurations the first time the vhost’s site is accessed. Inactive vhosts are not parsed until they are requested, cutting memory usage and leading to a faster startup/restart, especially on servers with many virtual hosts.
CPU affinity
CPU affinity binds a process to one or more CPUs (cores) allowing processes to make greater use of CPU cache.

Security

Connection and bandwidth throttling
LiteSpeed Web Server has per-IP connection, request, and bandwidth throttling. With these customizable features, IPs that make too many connections or requests or ask for too much bandwidth will be blocked, stopping attackers before they overrun your server.
mod_security compatibility
LiteSpeed Web Server supports almost all mod_security features. LiteSpeed is constantly updating our mod_security compatibility to keep up with mod_security's ceaseless changes and include the most important rules. Unsupported features are generally covered by other LSWS security features, and we are open to input on which features should be highest priority.
Atomicorp support
LiteSpeed Web Server is officially supported by Atomicorp for use with Atomic Secured Linux and Atomicorp's Realtime ModSecurity Rules. Atomicorp is one of the most trusted names in server security, having the longest running, most used ModSecurity rules on the Internet.
Anti SSL BEAST and renegotiation attack capabilities
LiteSpeed's developers react quickly to Internet security issues as they arise. We offer timely updates when new attack vectors emerge, developing new features and settings to answer the worst the Internet has to offer.
HTTP request checking
LiteSpeed Web Server checks all HTTP requests. Decoded URLs containing "/." are not allowed, so that hidden files will not be accessed. Users can also set the Max Request URL Length, Max Request Header Length, and Max Request Body Length settings to help prevent DoS attacks.
Denies buffer-overrun attempts
LiteSpeed Web Server has been designed to guard against buffer-overrun attacks, with extra failsafes to prevent exploitation even if bugs are found.
suEXEC
LiteSpeed Web Server has a fully-functioning suEXEC mode for PHP/Ruby/CGI/FCGI web applications.
CageFS compatibility
LiteSpeed Technologies enjoys a close partnership with CloudLinux, allowing for complete compatibility with this industry-leading shared hosting operating system.
chroot ability
Change root functions allow you to place either an individual web application, virtual host, or the whole web server in a virtual root directory (sometime called a "jail") and limit access outside of that root directory. This keeps attacks that may compromise a single application, user, or the web server from affecting the rest of the system.

High Availability

Apply changes with zero downtime
LiteSpeed Web Server's graceful restart feature allows ongoing processes to finish before exiting, while starting new processes immediately to take their place. This means new server configurations can be applied (to the new processes) without interrupting any processes.
Zero downtime server software upgrade
Software upgrades can also be applied with a graceful restart allowing old processes to finish before exiting, while new processes (with the upgrade) are spawned proactively to take their place.
Recovers from service failures instantly
LiteSpeed Web Server's auto-recovery feature automatically creates a new server process to take over when a server process exits abnormally.

Ease of Use

Control panel plugins
LiteSpeed Technologies has developed plugins for the world's most popular hosting control panels — cPanel (WHM), Plesk, and DirectAdmin. (Interworx has also created a plugin for their control panel.) These plugins allow you to control important LSWS functions, like installation, version management, restarting LSWS, and switching between LSWS and Apache, directly from the control panel.
cPanel support
cPanel officially supports LiteSpeed Web Server through their ticket system.
WebAdmin console
LiteSpeed Technologies' WebAdmin console puts all of LiteSpeed Web Server's configurations at the tip of your mouse. This GUI makes controlling LSWS far more intuitive than other web servers.
Virtual host templates
LiteSpeed's virtual host templates make it easy to set up and maintain multiple virtual hosts. The templates can either be used to create basic virtual host setups, which you then customize individually, or to easily create and maintain numerous virtual hosts with very similar settings. We also offer virtual host template configured for certain uses, such as reverse proxy or W3 Total Cache.
Real-time statistics
LiteSpeed's Web Admin console allows you to view your server statistics as they're happening. This helps you diagnose problems and eliminate attacking IPs, as well as check on the general health of your server.

Advanced Features

Multiple versions of PHP
LiteSpeed Web Server makes it easy to run multiple versions of PHP on one server, allowing ultimate flexibility for web applications and shared hosting providers.
MS FrontPage Server Extensions
LiteSpeed Web Server supports Microsoft FrontPage Extensions 2002 for UNIX.
Geo-IP lookup
LiteSpeed Web Server supports IP geolocation, allowing you to customize your web services based on the location of users' IP addresses.
External logger
LiteSpeed Web Server supports the use of piped loggers, allowing you to stream your logs straight to a database or to a remote server.
Custom log formatting
LiteSpeed Web Server allows you to customize the server's logging of requests using syntax compatible with Apache's mod_log_config.
Load balancing
LiteSpeed Web Server has the ability to function as a load balancer for other servers or web applications on the backend. LSWS can load balance based on a number of algorithms, including round-robin, least load, and least sessions.
Video streaming
LiteSpeed Web Server supports streaming video for mp4/H.264 and flv videos.

STAY CONNECTED