Html5 build issue

Hi there,

when i start the “TP_TopDown.html” the browser (Firefox 31.0) opens and has a progressbar which reads “Downloading Data”
and some buttons (“Fullscreen”, “Pause”, “Resume”, “Quit” and “ClearStoredGame”) but there is nothing happening
on the screen.

  • UE4.3 built in VS2013 (development x64)
  • UFE also built in VS2013 (development x64)
  • Emscripten from 1.7.8 to 1.21.0 (emsdk update, emsdk install latest, emsdk activate latest)
    (Emscripten SDK Full)

The build of the “TP_TopDown” template succeeded in UFE and the generated files are stored in

The “DefaultEngine.ini” reads:


I’ve tried setting “GameDefaultMap=/Game/Maps/Example_Map”
to “GameDefaultMap=/Content/Maps/Example_Map”
but with no success.

Any ideas?

Thanks in Advance

Try using a 64 bit browser such as:

HTML 5 is still experimental I guess but what I do is the following:

  1. Open UnrealFrontend
  2. Switch to the ‘Game Launcher’ tab and choose ‘Advanced’ from the left panel
  3. Create a profile for your build
  4. In the ‘Build’ section check the ‘Do you which to build?’ checkbox
  5. In the ‘Cook’ section select ‘Cook by the Book’ and select the maps you would like to build
  6. In the ‘Package’ section choose ‘Package & Store Locally’, let all fields blank though
  7. In the ‘Deploy’ section select ‘Copy to Device’ and create a new group for HTML5
  8. No click the ‘Launch’ button

The final build will be with the ‘Binaries/HTML5’ engine folder and not in you project folder.

When building and cooking you could also choose shipping which will result in smaller size of you final build.

If still fails (check the browser developer console) try tweaking the assigned heap memory that emscripten uses:

  • Open HTML5ToolChain.cs
  • Modify the following line:
    Result += " -s TOTAL_MEMORY=1610612736";
    To use a 32 bit browser its important to enable gzip on the web server, you can also pre-gzip the files but that requires some tweaking on the server side and some extra steps that you have to do manually (web technologies) not related directly to the engine.

Hope it helps to get you build running!

Edit: More about UnrealFrontend: Using the Unreal Frontend Tool | Unreal Engine Documentation


Hey Moss,

thank You very much for your answer and sorry for my late response.

On the GitHub i discovered that i have forgotten to install the optionals for html5,
so even the basics of building a html5 project weren’t given.
Now my problem is lack of diskspace again so i can’t check it out till i free
some space :frowning:

If you have any trouble regarding my 'lil guide just add a comment ^^


The file us located in the source of the engine. You can download it from github.

Please do not hijack threads nor post a comment as answers, it will un-mark the question in case it was resolved. You should create a new question instead.