I've found a way to downgrade Safari 15 to Safari 14. Furthermore, this way you actually can have two versions simultaneously. First, download Safari 14 for Mojave If the link above does not work, go to this seed page and find the latest Safari 14 version available. You should download the .pkg file, ofc, to proceed further. Second, after the .pkg file is downloaded, we shall unpack it, since the installation of this old version is not possible on Big Sur and newer (I assume, due to Security-related changes). To do so, use this command after navigating to your Download location: pkgutil --expand-full Safari14.1.2MojaveAuto.pkg ~/Downloads/Safari Third, when unarchiving finishes, go to the newly created Safari directory and find a Safari.app. It is located in ./Payload/Applications/ If you're using the Mojave installation, you'll get the old circular safari icon. Now, you may put this Safari.app whenever you want, but I urge you not to replace the original Safari.app file. It would be wiser either to put Safari 14 app file to another location, or name it Safari 14.app, for example. This will not cause any issues for you, and yes, you will be able to set this Safari 14 as a default web browser. Tested on latest stable Big Sur version after Safari 15 update. As far as I can see, this actually works fine.