You can use emscripten API to read the JavaScript window.location object. #include <emscripten/val.h> ... emscripten::val location = emscripten::val::global("location"); auto host = location["hostname"].as<std::string>(); auto port = location["port"].as<std::string>();

@aha_1980 said in UDP Socket - writeDatagram uses IPv6 and not IPv4: Then why not use QHostAddress::AnyIPv4 ? Looks more clear to me... Learn something new everyday :)