Javascript Wrapper

Pre-Compiled Binaries

  • Download the precompiled binaries from Javascript, or the development versions from the buildbot server at Javascript. Remember to get both files, coolprop.js and coolprop.js.mem.
  • You can load your js file into your website, following the structure of the example here, which is also included at the above download.
  • Alternatively, you can link to our server directly to make sure that you always have the latest version of CoolProp. To do so, include the address <script src=""></script> in your HTML header instad of the relative path <script src="coolprop.js"></script>.
  • A live demo of the Javascript library in action can also be found online.

User-Compiled Binaries


We are following the instructions from - download the portable emscripten SDK emsdk for linux.

  1. First download node.js, clang++ and llvm using:

    sudo apt-get install nodejs clang++ llvm
  2. Expand the SDK zip file linked above

  3. At the console in the folder that contains the file emsdk run the commands:

    emsdk update # This will fetch the list of things to download
    emsdk install latest # This will download and install the full toolchain
  4. Go enjoy a nice walk or a cup of coffee - it will be a while

  5. Activate the SDK just compiled:

    emsdk activate latest # This will make the file ~/.emscripten with the paths to most of the binaries compiled in SDK
  6. Modify the file ~/.emscripten to make NODE_JS path equal to which nodejs if it doesn’t already

  7. Make an environmental variable (in ~/.profile) export EMSCRIPTEN=/path/to/emsdk that points to the folder that contains emc++, emcc, etc.

  8. Check out coolprop:

    git clone --recursive
  9. Folder creating:

    mkdir -p build && cd build
  10. Build the Javascript module:

    cmake .. -DCOOLPROP_JAVASCRIPT_MODULE=ON -DCMAKE_TOOLCHAIN_FILE=${EMSCRIPTEN}/cmake/Modules/Platform/Emscripten.cmake


  1. Download the EMSDK installer, run the web download installer, that will install everything, and get you ready.

  2. In the %HOME%/.emscripten file, make sure that there is only one entry for NODE_JS and it points to the right place. Mine looks like:

    import os
    LLVM_ROOT='C:/Program Files/Emscripten/clang/e1.21.0_64bit'
    NODE_JS='C:/Program Files/Emscripten/node/0.10.17_64bit/node.exe'
    PYTHON='C:/Program Files/Emscripten/python/'
    EMSDK_GIT='C:/Program Files/Emscripten/git/1.8.3'
    EMSCRIPTEN_ROOT='C:/Program Files/Emscripten/emscripten/1.21.0'
    V8_ENGINE = ''
    TEMP_DIR = 'c:/users/belli/appdata/local/temp'
  3. Open an Emscripten command Prompt (Start->Emscripten->Emscripten command Prompt)

  4. Make an environmental variable EMSCRIPTEN that points to the folder that contains emc++, emcc, etc.

  5. Navigate to the root of the source

  6. Build the build folder:

    mkdir build && cd build
  7. Build the Javascript module:

    cmake ../.. -DCOOLPROP_JAVASCRIPT_MODULE=ON -DCMAKE_TOOLCHAIN_FILE=%EMSCRIPTEN%/cmake/Modules/Platform/Emscripten.cmake