After creating a new project with the Qt 5.15.1 WebAssembly kit, the web browser selector in the run settings is fixed at its single entry "safari", providing no alternative options regardless of what other browsers may be installed and what the system browser preference is set to.

My current workaround is to manually edit the WASM.WebBrowserSelectionAspect.Browser entry in the .pro.user file. Setting it to an empty string restores the earlier QtCreator behavior of using the system's preferred browser.

Needless to say, being able to test a WebAssembly project on browsers other than Safari is rather essential for development. Unless & until QtCreator is able to correctly populate its web browser selector with all installed browsers, it would be preferable if this would default to an empty string (which invokes the system's default browser) rather than "safari".