MacRumors published a story that Apple has released Safari 14 Beta for registered developers and some AppleSeed testers.
Apple Releases Safari 14 Beta for Developers and Some AppleSeed Testers
Apple this week provided a Safari 14 beta to developers and some of its AppleSeed testers, a program that is separate from the public beta and is offered on an invite-only basis.
Apple Releases Safari 14 Beta for Developers and Some AppleSeed Testers
Safari 14 is the new version of Safari that's included with macOS Big Sur. It introduces customization options that let people choose wallpapers and start page options, plus it is faster and more power efficient.