MacOS Big Sur pre-release for developers is now available for Apple Developer Program members at developer.apple.com, and a public beta will be available to Mac users later in July at beta.apple.com. The official version of macOS Big Sur will appear this fall as a free software update.
It is preliminary and not offered for mass installation.
Install at your own risk. Designed for Developers.
It is highly recommended that you upgrade to Time Machine before upgrading.
Here’s the full list of macOS Big Sur compatible Macs: