I was packaging a small project for html5.
I have installed everything according to this page. https://docs.unrealengine.com/latest/INT/Platforms/HTML5/GettingStarted/index.html
Though I have a question, I have installed emscripten from the SDK and not from the github and used the fastcomp. My packaging get stuck and is not proceeding any further even after a few hours.
Related answerhub question.