Apple has dropped macOS Tahoe 26.5 this morning, with updates to Sequoia and Sonoma.
You know what that means? It’s time to update your bootable installers.
Apple has some straightforward guides on how to download macOS so fetch the latest installers and let’s get building.
From the page above, here are links to the App Store downloads for Sequoia and Sonoma:
Download macOS Sequoia & download macOS Sonoma.
I don’t know why, but since the initial release of macOS Tahoe, Apple has decided you can no longer download the full Tahoe installer from the App Store, so the easiest way to get the full installer is via Terminal. To show available installers, drop into Terminal and type:
softwareupdate --list-full-installers
This will give you a list of all available Tahoe and, apparently, Sequoia installers.
Then, to download the one you want:
softwareupdate --fetch-full-installer --full-installer-version <number>
e.g. for macOS Tahoe 26.5:
softwareupdate --fetch-full-installer --full-installer-version 26.5
Then, once you have the app downloaded and it’s in your Applications folder, follow the instructions from Apple to make a bootable macOS installer on a USB drive.
e.g. to build an installer for macOS Tahoe (the following command assumes that you have a volume on your external SSD called macOS Tahoe, and you want to wipe it completely with no prompt)
cd /Applications/Install\ macOS\ Tahoe/Contents/Resources
sudo ./createinstallmedia —volume /Volumes/macOS\ Tahoe --downloadassets --nointeraction
One thing to look out for is that the installer for Tahoe has grown over time. I used to make the partitions on my external SSD 16 GB in size each, but over the past few years this has not been enough. for macOS Tahoe, I had increased the partitions to 20 GB, however Tahoe now needs more than 20 GB (something like 20.5 GB, frustratingly enough), so I had to use Disk Utility to resize the Tahoe partition and steal 1GB from a partition next to it.
Disk Utility kind-of sucks for these kind of precise operations, but it’s possible to work through it with enough patience.
Finally, the last thing I do after building the installer is to put a nice icon on the partition so I can easily identify them on the Desktop and in the Boot Picker.
Open up the partition with the macOS installer on it, and then do a get-info (⌘ + I) on the app. Click on the app icon at the top-left of the get info window and type ⌘ + C to copy it. Then go to the disk icon on the Desktop, do a get-info, select the icon and type ⌘ + V to paste it onto the disk.