The golden rule with any pre-release version of macOS is never to install it on a production Mac, one that you rely on for doing anything important to you. Although even developer betas are generally fairly robust and shouldn’t cause data loss, sometimes they can be catastrophic and require putting your Mac into DFU mode and restoring it from scratch.

Rather than compromise and run Tahoe from a bootable external disk, which only reduces the risk, why not run it in a VM, where it should be safely isolated from the rest of your Mac? Provided that you have an Apple silicon Mac running Sequoia 15.5 and a little time, this is easy to set up. Its major disadvantage is that your VM won’t be able to run the great majority of apps in the App Store, as that still isn’t supported in lightweight VMs. But your VM can have full iCloud access, and its Data volume can be protected by FileVault as well.

Before you try installing your VM, you’ll need to install a software enabler. This can be Device Support for macOS 26 beta, available from Apple’s developer site alongside the IPSW image file for Tahoe, or you can install the beta-release of Xcode version 26 instead. If you do neither, when you try to run your Tahoe VM you’ll be warned, and invited to download the enabler, but that isn’t likely to work, leaving you with an unusable VM.

Then download the IPSW file from Apple’s developer site, or via Mr. Macintosh’s link to Apple, install that and run your VM.

I’m grateful to Joe for letting me know an alternative route, by upgrading an existing Sequoia VM. For that you’ll need the full installer, again through Mr. Macintosh’s link, so you can install that in the VM and run it from there.

These should work with all virtualisation apps, including commercial products like Parallels Desktop, and free apps including my own Viable and Vimy, which also appear fully compatible with Tahoe hosts.

Happy virtual Tahoeing!