Installing Wt on MS Windows

This HOWTO assumes you have a clean Windows system and want to use Wt 2.1 or newer series. We start with the download of the compiler and system libraries. We continue to explain where the dependency libraries can be found and how they are installed. Then the configuration of Wt is covered, and finally we build Wt and run the examples.

Unlike Linux distributions, Windows has no easy package managers for developers. To avoid compiling dependencies for half a day before you can use Wt, we strongly reduced the minimal dependencies that Wt requires. Since Wt 2.1, Boost and CMake are the only required dependencies. We will explain two approaches to set up your environment: the quick method, using binary packages, and the thorough method, in which you compile more dependencies, but which will also result in a Wt that supports compression, SSL, etc.

These instructions are valid for all 2.1 and newer versions of Wt.

Setting Up Your Compiler

Wt 2 and Wt 3 need Microsoft Visual Studio 2005 or newer, Professional or Express Edition (C++). Wt 4 requires MSVS 2015 or newer. The free versions of Microsof Visual Studio (the Community or Express Edition) is perfect to compile Wt.

For more information about the compiler, see Installing MSVC.

The Easy Method

Wt binary releases are now available for MSVS compilers. They can be downloaded from the github Wt release area

These downloads contains Wt and related dependencies (boost, openssl, libharu, libpng, zlib, ...) and all compiled examples with appropriate bat files to run them.

To compile your own application using these binary releases, set the following properties in your MSVS project:
  • In C/C++ -> General, Additional Include Directories: c:/location/of/wt-x.y.z/include
  • In C/C++ -> Preprocessor, ensure that WIN32 is defined. Also define HPDF_DLL, which will allow you to generate pdf files.
  • In Linker->General, Additional Library Directories: c:/location/of/wt-3.3.1/lib
  • Go to Linker->Input. In the Additional Dependencies, fill out the Wt libraries you want to link to. At the topleft of the dialog, check the active Configuration. If it's Debug, link to wtd.lib, wthttpd.lib (and optionally wtdbod.lib, wtdbobackendXXXd.lib, ...). If it's release, link to wt.lib, wthttp.lib (and optionally wtdbo.lib, wtdbobackendXXX.lib). Notice that the debug libraries have a 'd' suffix. Be carefull. You need different libraries depending on the Release/Debug configuration, since it's not possible to mix different versions of the MSVC runtime libraries in one application.
If you want to run your fresh application, set these options:
  • In the Debugging tab, set Command Arguments to --docroot . --http-address --http-port 8080
  • In the Debugging tab, set Environment to PATH=c:/location/of/wt-x.y.z/bin

These installers are new, so if you encounter any problems please report them in the Wt Forums

The Quick Method

The quick method installs Wt without any optional components (without HTTP compression, HTTPS, server-side graphics rendering, postgres, mysql, ...)

Download Dependencies

  • Install Boost. Either download binaries, or compile your own:
    Do not use boost version 1.54 on windows (bug in boost asio). Do not use boost 1.46 or newer with Wt < 3.1.11 on Windows (bug Boost > 1.36 is required.
  • To compile Boost yourself, download the Boost sources from Use the following command:
bjam --layout=versioned variant=debug threading=multi link=static runtime-link=shared install
bjam --layout=versioned variant=release threading=multi link=static runtime-link=shared install
  • Download the cmake 3 (cmake > 2.4.6 required) Windows Installer. Run the installer to install CMake.
  • Download Wt from the download page. Unzip it somehwere (c:/projects/witty/wt-3.x.x).

Configuring Wt

  • Start the CMake GUI from the Start->CMake menu
  • At the top of the window that opens, fill in or browse to the source and binary directories:
    • Where is the source code: c:\projects\witty\wt-3.x.x
    • Where to build the binaries: c:\projects\witty\wt-3.x.x\build
  • Click Configure
  • Select the right version of Visual Studio
You will probably get errors about Boost not being found. That is normal, as you did not yet tell where the library is located. Set the BOOST_PREFIX variable to match your configuration. For example:
  • BOOST_PREFIX = c:/boost

Another error you might encounter in CMake is "The C compiler "cl" is not able to compile a simple test program." This means that your Visual Studio won't find 'cmd' as it isn't configured correctly.

What you must do is change the MSVC options (Tools menu > Options > Project and Solutions > VC++ Directories) to ensure that

  • $(SystemRoot)
  • $(SystemRoot)\System32
  • $(SystemRoot)\System32\wbem

are specified BEFORE $(PATH).

If cmake complains about a DLL not being found, just click 'ok' and ignore the error. This has no effect on the generated project files.

Press 'Configure' again. A few messages about the FCGI and wthttpd connector may pop up; just click Ok. A few new configuration fields (in red) will have popped up; leave them unchanged and press 'Configure' once more. If all went well, you have now no red fields left and the configuration is complete. Press Generate (in cmake <2.8, this button is called 'Ok') and your MSVC solution files will be generated.

Compiling Wt

Open the WT.sln solution in the 'Where to build the binaries' directory of the previous step. Press F7, or select the projects you want to build manually. You should not get any compile or link errors.

Installing Wt

After compilation, open the Solution Explorer and right-click on the 'INSTALL' project. Select 'build'. This will copy the Wt header files and libraries to c:/Program Files/WT.

Optional Components

This involves installing SSL, zlib and some other components. After installation as described here, rerun CMake. These instructions are valid for Wt > 2.1.0.


In order to avoid setting paths to small libraries separately, we create a repository where we store them all. CMake will find this repository without assistance if you call it 'c:\libraries'.

mkdir c:\libraries
mkdir c:\libraries\lib
mkdir c:\libraries\include

Download and Build zlib

Zlib is an optional dependency of Wt, which can be controlled by the CMake flag HTTP_WITH_ZLIB. With zlib, Wt compresses all http traffic by default, saving bandwidth.

  • Download the zlib library from the zlib home page Select your preferred format (tar.gz, tar.bz2 or zip) and download location.
  • In Microsoft Visual Studio, open zlib-1.2.x\contrib\vstudio\vc8\zlibvc.sln.
  • Select solution 'Debug', architecture 'Win32' (in the toolbar)
  • Right-click on project 'zlibstat', select Properties. In 'Configuration Properties'->'C/C++'->'Code Generation'->'Runtime Libraries' and set it to 'Multi-threaded Debug DLL (/MDd)'. Close the properties window.
  • Do the same with project 'zlibvc'
  • Right-click on project 'zlibstat', and select 'Build' to build it.
  • Select solution 'Release', architecture 'Win32'
  • Right-click on project 'zlibstat', select Properties. In 'Configuration Properties'->'C/C++'->'Code Generation'->'Runtime Libraries' and set it to 'Multi-threaded DLL (/MD)'. Close the properties window.
  • Do the same with project 'zlibvc'* Right-click on project 'zlibstat', and select 'Build' to build it.

The results are now located in the x86 directory. Copy them into our central repository location, renaming the debug library in the process:

cp contrib\vstudio\vc8\x86\ZlibStatDebug\zlibstat.lib c:\libraries\lib\zlibstatd.lib
cp contrib\vstudio\vc8\x86\ZlibStatRelease\zlibstat.lib c:\libraries\lib\

We also need zlib.h and zconf.h header files.
cp zlib.h zconf.h c:\libraries\include


You need OpenSSL if you want to use Wt to support https mode. Grab a pre-compiled binary from, install it in the default path (c:\OpenSSL) and Wt's CMake files will find and use OpenSSL. (Verify that HTTP_WITH_SSL is enabled.)


GraphicsMagick is no longer required for Wt releases 3.3.7 and newer. Direct2D is the default WRasterImage backend on Windows since 3.3.7.

The generic build instructions for GraphicsMagick are found here:

In order for GraphicsMagick to work with your version of MSVC, it is strongly recommended to build it from the sources. Follow the instructions on the GraphicsMagick site:
  • Run VisualMagick/configure/configure.exe to create a .sln file
  • Make sure to select the default 'Dynamic Multi-threaded DLL runtimes' and 'Use X11 stubs to prevent use of X windows'
  • Open VisualMagick/VisualStaticMT.sln in MSVC and press F7. Make sure you select the 'Release' or 'Debug' build as appropriate. For me, the UTIL_IMDisplay project fails to compile, which is unimportant.

While configuring Wt, point GM_PREFIX to the toplevel directory of GraphicsMagick (i.e. the one containing subdirectories VisualMagick and magick). Press Configure, and CMake should find the header files and compiled binaries.

Important: when executing a binary linked to a Wt library that uses GraphicsMagick, the GraphicsMagick DLLs must be found by Windows. This means that they should be in c:/windows/system32, or in the current working directory, or that you should add the VisualMagick/bin directory to your path. Otherwise your application will complain that it cannot find the required DLLs to start up.

In order to render fonts, verify that your imagemagick fonts are correctly configured. For example, on my computer I had to remove the include for type-ghostscript.mgk in the VisualMagick/bin/type.mgk file to have any fonts rendered at all.

Running the Examples

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=.

Wt builds static versions of all libraries by default and links against static Boost libraries by default. If you would choose to build dynamic libraries in the future (see remarks at the bottom of this page), the easiest way to locate the dependency DLLs is to append their location to the PATH variable. In order to do so, change the Environment field to contain a PATH directive:

PATH=c:/libraries/lib;c:/Boost/lib;<path to wt.dll>;<path to wthttp.dll>

Right-click on the example project you want to run and select 'Set as Startup Project'. Press F5 (Run). This will start the 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-2.x.x/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 wt application with --help to see the newer options available in your version):

General options:
  -h [ --help ]              produce help message
  -t [ --threads ] arg (=10) number of threads
  --docroot arg              document root for static files
  --no-compression           do not compress dynamic text/html and text/plain 
  --deploy-path arg (=/)     location for deployment

HTTP server options:
  --http-address arg    IPv4 (e.g. or IPv6 Address (e.g. 0::0)
  --http-port arg (=80) HTTP port (e.g. 80)

HTTPS server options:
  --https-address arg     IPv4 (e.g. or IPv6 Address (e.g. 0::0)
  --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 parameters
                          e.g. "/etc/ssl/dh512.pem" 

Important Remarks

By default, Wt will build static libraries that are statically linked against Boost. While this is convenient for quick deployment (the example binaries do not require DLLs to run, so you do not have to set their PATHs correctly), many people prefer to use DLLs, not in the least because your Wt applications will link much faster.

Two CMake options control how Wt is built, and what kind of Boost libraries it uses:
  • BOOST_DYNAMIC: set to true to build against Boost DLLs. Set to false to link to static Boost libraries.
  • SHARED_LIBS: set to true to build a Wt DLL, set to false to build a static Wt library.

If you double-checked the library directories but still get build errors such as "cannot open file 'libboost_signals-vc90-mt-gd-1_35.lib'", you probably did not install or build the static Boost files, while the BOOST_DYNAMIC option is set to false. Similarly, when the error indicates that boost_signals-vc90-mt-gd-1_35.lib is not found, you probably haven't installed or built the Boost DLLs, while BOOST_DYNAMIC is set to true.

Note that when you build a static Wt library (SHARED_LIBS is false), you will get these Boost-related linker errors only when you compile the examples.

Support for Microsoft IIS

Wt works well with Microsoft IIS as ISAPI extensions. See the ISAPI on Microsoft IIS wiki for more information on how to deploy Wt in IIS.