BTW, @dev, do you have any plans to build the Qt version for Emscripten and make Tiled run as Web App with Google Drive/OneDrive export/import functionality? This will be nice? If no, I MAY try to build it myself for that case.
You can check out these resources:
https://github.com/msorvig/qt-webassembly-examples
http://vps2.etotheipiplusone.com:30176/redmine/projects/emscripten-qt/wiki/Demos
Amongst others.