Wt  4.10.4
Installation: Windows
Wt Installation

Wt Installation instructions for Windows

This page lists the instructions for building and installing Wt on Windows. It is organized in 3 sections:
  • Requirements
  • Building and installing the library
  • Trying the examples (or your own Wt application)


Wt for Windows uses the built-in web server connector or the ISAPI connector. The fastcgi connector is not supported. The built-in web server is more convenient during development and is easier to setup than the ISAPI connector. It is also designed for production environments, where it is often used in combination with a reverse proxy server. To use the built-in server, you have to link your projects against libwt and libwthttp. To use the ISAPI connector, you have to link to libwtisapi instead of libwthttp.

The prebuilt binaries for Visual Studio include all necessary and optional dependencies, and enable all features of Wt and can be downloaded from the releases page on GitHub.


  • Microsoft Visual Studio 2015 or newer. Wt and its dependencies also build on the Community Edition, which is free (as in beer) to use.
  • CMake cross-platform build system (www.cmake.org): cmake-3.1.x or higher
  • Boost 1.46.1 (or later; a recent version is recommended)

Additional and optional requirements for some of the examples

  • For HTTPS support: OpenSSL, version 0.9.8d or newer.
  • To compress traffic: zlib
  • PostgreSQL, MySQL, Firebird client libraries for Dbo database backends
  • Haru Free PDF Library, which is used to provide support for rendering PDF (WPdfImage, WPdfRenderer).

We strongly recommend to use libraries which are all built using the same compiler and the same runtime configuration (/MT, /MD, /MTd or /MDd) to avoid incompatibilities with the C runtime libraries. Mixing CRTs is NOT recommended, the zlib DLL FAQ clearly explains why and what you should do about it (in short: use prebuilt libraries for the exact same compiler as you use, and if those are not available, rebuild the dependency libraries from the sources).

Step by step instructions to build and install the Wt library

Up to date instructions are located on the Wt wiki page: Installing Wt on MS Windows

Instructions on how to use the ISAPI connector for deployment under IIS are also available on the wiki page: ISAPI on Microsoft IIS

Trying the examples (or your own Wt application) using wthttpd

1. Run the example in the MSVC IDE

Right-click on the example project you want to run, and select 'Properties'. In Configuration Properties->Debugging, set the Command Arguments to
--http-address= --http-port=8080 --deploy-path=/hello --docroot=.

This will start a httpd server listening on all local interfaces, on port 8080, and you may browse the example at

Examples that need extra files to run should be executed from their source directory in order to find their dependency files (icons, css files, etc. Watch for 404 errors in Wt's output). To do so, set the 'Working directory' for the example to wt-x.y.z/examples/ExampleName. Some examples (e.g. the wt home page) need the 'resources' directory to work correctly. Copy the wt-2.x.x/resources to the example's source directory to solve this problem. Other examples (such as the Charts example) may require the installation of ExtJs. See the Wt reference manual for more information on how to obtain and install ExtJs.

These are all the command-line options that are available (run the examples with --help to see the most recent list of available options):

General options:
  -h [ --help ]                         produce help message
  -t [ --threads ] arg (=-1)            number of threads (-1 indicates that
                                        num_threads from wt_config.xml is to be
                                        used, which defaults to 10)
  --servername arg (=diffie)            servername (IP address or DNS name)
  --docroot arg                         document root for static files,
                                        optionally followed by a
                                        comma-separated list of paths with
                                        static files (even if they are within a
                                        deployment path), after a ';'

                                        e.g. --docroot=".;/favicon.ico,/resourc

  --approot arg                         application root for private support
                                        files; if unspecified, the value of the
                                        environment variable $WT_APP_ROOT is
                                        used, or else the current working
  --errroot arg                         root for error pages
  --accesslog arg                       access log file (defaults to stdout),
                                        to disable access logging completely,
                                        use --accesslog=-
  --no-compression                      do not use compression
  --deploy-path arg (=/)                location for deployment
  --session-id-prefix arg               prefix for session IDs (overrides
                                        wt_config.xml setting)
  -p [ --pid-file ] arg                 path to pid file (optional)
  -c [ --config ] arg                   location of wt_config.xml; if
                                        unspecified, the value of the
                                        environment variable $WT_CONFIG_XML is
                                        used, or else the built-in default
                                        (c:/witty/wt_config.xml) is tried, or
                                        else built-in defaults are used
  --max-memory-request-size arg (=131072)
                                        threshold for request size (bytes), for
                                        spooling the entire request to disk, to
                                        avoid DoS
  --gdb                                 do not shutdown when receiving Ctrl-C
                                        (and let gdb break instead)

HTTP/WebSocket server options:
  --http-address arg                    IPv4 (e.g. or IPv6 Address
                                        (e.g. 0::0). You must specify either
                                        this option or --https-address (or
  --http-port arg (=80)                 HTTP port (e.g. 80)

HTTPS/Secure WebSocket server options:
  --https-address arg                   IPv4 (e.g. or IPv6 Address
                                        (e.g. 0::0). You must specify either
                                        this option or --http-address (or both)
  --https-port arg (=443)               HTTPS port (e.g. 443)
  --ssl-certificate arg                 SSL server certificate chain file
                                        e.g. "/etc/ssl/certs/vsign1.pem"
  --ssl-private-key arg                 SSL server private key file
                                        e.g. "/etc/ssl/private/company.pem"
  --ssl-tmp-dh arg                      File for temporary Diffie-Hellman
                                        e.g. "/etc/ssl/dh512.pem"
  --ssl-enable-v3                       Switch on SSLv3 support (not
                                        recommended; disabled by default)
  --ssl-client-verification arg (=none) The verification mode for client
                                        This is either 'none', 'optional' or
                                        'required'. When 'none', the server
                                        will not request a client certificate.
                                        When 'optional', the server will
                                        request a certificate, but the client
                                        does not have to supply one. With
                                        'required', the connection will be
                                        terminated if the client does not
                                        provide a valid certificate.
  --ssl-verify-depth arg (=1)           Specifies the maximum length of the
                                        server certificate chain.

  --ssl-ca-certificates arg             Path to a file containing the
                                        concatenated trusted CA certificates,
                                        which can be used to authenticate the
                                        client. The file should contains a a
                                        number of PEM-encoded certificates.

  --ssl-cipherlist arg                  List of acceptable ciphers for SSL.
                                        This list is passed as-is to the SSL
                                        layer, so see openssl for the proper
                                        syntax. When empty, the default
                                        acceptable cipher list will be used.
                                        Example cipher list string:

  --ssl-prefer-server-ciphers arg (=0)  By default, the client's preference is
                                        used for determining the cipher that is
                                        choosen during a SSL or TLS handshake.
                                        By enabling this option, the server's
                                        preference will be used.