How to clean install macOS Tahoe 26 on Mac

Apple has released macOS Tahoe 26 for compatible Macs, bringing new design elements, improved productivity features, and deeper integration with iCloud and Apple services. While most users will choose to upgrade directly from System Settings, some may prefer performing a clean installation. This method completely erases your Mac’s internal storage before installing a fresh copy of macOS, which can help fix issues, remove clutter, or give your computer a fresh start.

A clean install is not required for most users, but it can be useful if you have been experiencing performance problems, are preparing to sell your Mac, or simply want to eliminate old files and applications for a smoother experience. Before starting, make sure your Mac is compatible with macOS Tahoe 26 and that you have a reliable backup of all your important data.

Back up your Mac before clean installation

Since a clean installation will erase everything from your Mac, backing up your files is essential. Apple’s built-in Time Machine tool is the easiest option, but you can also use iCloud Drive or an external hard drive. To back up using Time Machine:

1. Connect an external hard drive to your Mac.
2. Open System Settings > General > Time Machine.
3. Select your external drive as the backup disk.
4. Start the backup and wait for it to complete before proceeding.

Alternatively, ensure your most important files are stored in iCloud or manually copied to an external storage device.

Create a macOS Tahoe 26 bootable installer

To perform a clean install, you will need a bootable installer of macOS Tahoe 26 created on a USB flash drive with at least 16GB of storage.

1. Download macOS Tahoe 26 from the Mac App Store or from System Settings > General > Software Update.
2. Insert your USB flash drive and open Disk Utility.
3. Format the drive as Mac OS Extended (Journaled) with GUID Partition Map.
4. Once formatted, open Terminal and run the following command (replace MyVolume with your USB drive’s name):

   sudo /Applications/Install\ macOS\ Tahoe.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume
   

5. Enter your admin password when prompted and wait for the process to finish. The USB drive will now be ready as a macOS installer.

Erase your Mac and install macOS Tahoe 26

With the bootable installer prepared, you can now erase your Mac and perform a clean installation.

1. Connect the bootable USB installer to your Mac.
2. Restart your Mac and immediately press and hold the Option (⌥) key.
3. From the startup menu, select the USB installer drive.
4. Once the installer loads, open Disk Utility.
5. Select your Mac’s internal drive (usually named “Macintosh HD”) and click Erase. Choose APFS as the format.
6. After erasing, close Disk Utility and select Install macOS Tahoe from the installer menu.
7. Follow the on-screen instructions to complete installation.

Set up your Mac after clean install

Once macOS Tahoe 26 is installed, your Mac will restart and display the setup assistant. You can now:

• Sign in with your Apple ID to restore iCloud data.
• Transfer files from your Time Machine backup or external drive.
• Reinstall apps from the Mac App Store or developer websites.

This clean installation ensures your Mac runs macOS Tahoe 26 without leftover files or apps from previous versions. It’s one of the most effective ways to achieve the best performance and stability on your device.