Steps for Downgrading from macOS 26 Tahoe on a New Mac

How to Revert from macOS 26 Tahoe on a New Mac

Navigating the intricacies of reverting your macOS can feel overwhelming, particularly when moving from the most recent macOS 26 Tahoe to a previous version. This guide will assist you in the necessary steps to effectively revert your system using a USB installer.

Preparing Your USB Drive for macOS Installation

Before initiating the downgrade process, you must set up a USB drive to function as your macOS installer. Here’s how to begin:

Formatting Your USB Drive

1. Open Disk Utility: Start Disk Utility on your Mac.
2. Show All Devices: Click the View option and select “Show All Devices.”
3. Select Your USB Drive: Under the “External” section in the sidebar, select your USB drive’s root.
4. Erase and Format: Click the Erase option. Rename the disk (e.g., “MyVolume”), set the Format to Mac OS Extended (Journaled), and the Scheme to GUID Partition Map.

Partitioning for Multiple Installers

If you possess a larger USB drive, you can partition it to accommodate multiple macOS installers. For example, a 64GB drive can be divided into three ~21GB partitions, enabling you to boot different macOS versions like Tahoe and Sequoia from a single drive.

Creating a Bootable macOS Installer

Once your USB drive is prepared, you can make a bootable installer for the macOS version you aim to revert to.

Using Terminal to Create the Installer

1. Locate the Installer: Confirm that the macOS installer is in your Applications folder.
2. Run Terminal Command: Open Terminal and execute the appropriate command for your macOS version. For macOS 15 Sequoia, use:

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

   Modify the command if you renamed your USB drive.

3. Enter Your Password: Terminal will request your password and prompt you to confirm the process by typing ‘Y’.

4. Wait for Completion: The drive will be reformatted, and the installer files will be transferred. This process usually takes a few minutes with USB 3 drives.

Final Steps to Revert

After creating the bootable installer, keep the USB drive connected and power off your Mac. Upon rebooting, you can boot from the USB drive to initiate the installation of the desired macOS version.

Conclusion

Reverting your macOS from version 26 Tahoe to a previous version like Sequoia necessitates careful preparation and execution. By adhering to these steps, you can ensure a seamless transition and retain the functionality you require from your Mac.

Q&A Session

Q1: Why would I consider reverting my macOS?
A1: Users might opt to revert due to software compatibility challenges, a personal preference for an older interface, or concerns over stability with the latest version.

Q2: Can I utilize any USB drive for the installer?
A2: It’s advisable to use a USB drive with at least 16GB of storage, but a 64GB drive permits multiple installers.

Q3: What occurs if I fail to format the USB drive properly?
A3: The installer may fail to work, and you may encounter errors during the installation process.

Q4: Is it feasible to revert without a USB drive?
A4: While possible, utilizing a USB drive remains the most dependable method for creating a bootable installer.

Q5: Will reverting erase my data?
A5: Yes, reverting typically entails erasing your hard drive, so backing up your data beforehand is essential.

Q6: Can I upgrade back to macOS 26 Tahoe later?
A6: Yes, you may upgrade back to the latest version through the macOS Software Update feature.

Q7: Are there any risks linked to reverting?
A7: Reverting can lead to potential data loss and software compatibility issues, so ensure you have backups and verify software requirements.