WebGL exclude parts of UnityEngine for smaller builds?

Questions & Answers
1

Is there a way or plans to support excluding parts of the UnityEngine for smaller builds?

Enable “Stripping Level” in Player Settings.

for a noob what do these different stripping levels mean?

2

The stripping level dropdown menu for the WebGL player settings is currently a bit misleading (and we have a bug for it to clear it up):

Disabled - There is no stripping

Any of the 3 stripping modes - the compiler will strip everything it possibly can for the smallest build size.