How to build ue only for desktop?

As the title saied, when I build developer editor, I found it too large for me which took almost 30Gb hd space.

I’m new here and I don’t know what to do with the source code.

Is that possible to disable IOS or android building. How can I build unreal engine only for desktop?

Platform support is not why your engine build is taking 30 Gig of space. If you don’t know what to do with the source code I recommend using the Binary version from the Launcher.