[1]: https://github.com/miurahr/aqtinstall
https://download.qt.io/online/qtsdkrepository/
It has binaries from different compilers, for example:
https://download.qt.io/online/qtsdkrepository/windows_x86/de...
The online installer is the official way. Don't know if it can download binaries for other platforms.
https://www.qt.io/download-open-source
> Looking for Qt binaries?
> Find them in the Qt Online Installer. It will steer you to the right download version and help you install tools and add-on components that are available for your open source license.