HTML5 huge build size

I am building for HTML5. My builds are unacceptably large for a relatively simple project: around 200-300 mb. This is unusable for playing in the browser as intended. Unity 5 builds are around 20 mb. What gives? I am sure stripping out any unused materials, meshes, and trimming fat will help, but It’s not going to reduce the build size down to 20 mb. How do I achieve this?

I’m looking into Gzip (something Unity has built into their packaging system). Is this something that may be integrated into Unreal 4’s packaging at some point? Is it enough to reduce my project size more than 1000%, or is the existing Unreal packaging system building in a whole lot of referenced bloat no matter what?

Thanks for any clarification you can offer,

Hey ,

Here is a good [AnswerHub][1] for you to review regarding the package size of an HTML5 project. It’s been suggested to gzip the contents, which seems like it’s something you’re currently looking into already. Taking out any unused materials, meshes, assets, etc will reduce the size of your package too, but not to the size that you’re looking for. There is another way to help reduce the package size if you’re not using slate, which you can see [here][2].

I have an update from one of our developers: We’re planning to integrate gzip into the packaging pipeline. However, gzip HTML5 builds are the smallest of all platforms Unreal Engine supports. Shipping the engine binary should gzip roughly around 9MB.

It’s also been suggested that you build a shipping version of your project. You can find more information [here][3].


How to reduce HTML5 package size? - Plugins - Epic Developer Community Forums
[2]: HTML5 Build Size Optimization - Platform & Builds - Epic Developer Community Forums
[3]: Packaging Unreal Engine Projects | Unreal Engine 5.1 Documentation


Thanks, this info looks super helpful! I will update once I have implemented these strategies with results on the new build sizes.

Hey ,

You’re welcome. Let me know if there is anything else I can assist you with. Have a wonderful day!