Quick Answer
If you get an error message on your Mac saying “Erase Assistant is not supported,” it typically means the version of macOS you are running does not have the necessary Erase Assistant feature to securely erase your drive. Erase Assistant was introduced in macOS High Sierra 10.13.4 and later versions to enable users to quickly and securely erase their Mac drive and reinstall macOS.
Older versions of macOS do not include Erase Assistant, so you will get this error if you try to use it. To fix this, you need to update your Mac to the latest version of macOS that includes Erase Assistant. Alternatively, you can use Disk Utility’s Erase feature or a third party app to securely erase your drive before reinstalling macOS.
What is Erase Assistant on Mac?
Erase Assistant is a feature of macOS High Sierra 10.13.4 and later designed to make it easy to quickly and securely erase your Mac’s internal drive and reinstall a fresh copy of macOS.
When erasing and reinstalling macOS, it’s important to securely erase the drive first to protect your data. Simply deleting files or reformatting the drive does not fully erase your data – it can still be recovered.
Erase Assistant uses multiple pass overwrite algorithms to securely wipe your drive, removing all traces of your files and data. Once erased, it lets you immediately reinstall a fresh macOS, getting your Mac ready for use again or to sell/give away with no personal data left behind.
Benefits of Erase Assistant
Here are some of the benefits Erase Assistant provides:
- Makes erasing your drive and reinstalling macOS much simpler and faster.
- Securely erases data by overwriting every block of the drive.
- More secure than basic formatting options which can leave data behind.
- Automatically reinstalls macOS after erasing so your Mac is ready to use.
- Free built-in solution for erasing Mac drives.
For these reasons, Erase Assistant is recommended for easily wiping and reinstalling macOS.
Why Do I Get “Erase Assistant is Not Supported”?
If you get the message “Erase Assistant is not supported,” it’s because your version of macOS does not include the Erase Assistant feature.
Erase Assistant was introduced in macOS High Sierra 10.13.4. Any macOS version prior to 10.13.4 will not support Erase Assistant.
Here are the macOS versions that include Erase Assistant support:
- macOS High Sierra 10.13.4 or later
- macOS Mojave 10.14 or later
- macOS Catalina 10.15 or later
- macOS Big Sur 11 or later
- macOS Monterey 12 or later
- Latest macOS Ventura
So if you are running an older version like macOS Sierra 10.12 or earlier, you will get the “Erase Assistant not supported” message.
Checking Your macOS Version
To find out which macOS version you have, go to the Apple menu and choose About This Mac. This will show your macOS name and version number.
Compare your version with the list above. If your version is older than macOS High Sierra 10.13.4, then your Mac does not support Erase Assistant. You will need to update to a newer macOS release to use this feature.
How to Fix “Erase Assistant Not Supported”
If you get the “Erase Assistant not supported” error on your Mac, here are a few ways to fix or work around it:
1. Update Your macOS
The simplest fix is to update your Mac to a version of macOS that includes Erase Assistant.
You can update to the latest macOS release for free in System Preferences > Software Update.
With macOS High Sierra 10.13.4 or later installed, Erase Assistant will be supported.
2. Use Disk Utility Erase
Disk Utility has always offered drive erasing capabilities, even on older macOS versions.
To securely erase your drive without Erase Assistant:
- Open Disk Utility
- Select your internal drive in the sidebar
- Click Erase in the toolbar
- Choose a secure erase option like Mac OS Extended (Journaled, Encrypted)
- Click Erase to wipe the drive
This will still securely erase data by overwriting the drive. However, you’ll need to reinstall macOS from the App Store or external drive.
3. Use a Third Party Erase Tool
Apps like Mac Cleaner Pro and MacKeeper offer data erasure tools that work on older macOS versions.
Simply install the app and use their erase feature to securely wipe your drive before reinstalling macOS.
However, these are paid apps while Erase Assistant is free.
Step-By-Step Guide to Using Erase Assistant
Once updated to a compatible macOS release, you can use Erase Assistant to easily erase and reinstall macOS:
- Restart your Mac and hold Command + R keys to boot to Recovery mode
- Select Disk Utility from the macOS Utilities window
- Click Continue to open Disk Utility
- Select your internal drive in the sidebar (eg “Macintosh HD”)
- Click Erase in the toolbar
- In the popup, click Erase Assistant
- Follow the onscreen steps to select a drive erase and macOS reinstall option
- Click Continue to allow Erase Assistant to securely erase then reinstall macOS
The process takes a while but will fully wipe your drive and reinstall a fresh macOS automatically.
Alternative Ways to Erase and Reinstall macOS
If you can’t use Erase Assistant, there are a couple alternative ways to erase your Mac drive and reinstall macOS:
Internet Recovery
Macs released in or after 2012 have Internet Recovery built-in. This lets you erase and reinstall macOS over the internet, without needing a local installer.
To use Internet Recovery:
- Restart Mac and hold Command + Option + R
- Use Disk Utility to erase the drive
- Choose Reinstall macOS from the Utilities window
- Follow the prompts to reinstall macOS over the internet
This will download and install the latest compatible macOS.
USB Installer Drive
You can create a bootable USB installer drive for macOS. This lets you boot, erase, and install macOS from the USB drive.
To create a USB installer:
- Download macOS installer from App Store onto your Mac
- Plug in a 16GB+ USB drive
- Run ‘createinstallmedia’ command in Terminal to create bootable installer
- Boot Mac from the USB drive and install macOS from there
This allows installing macOS when internet recovery is not available.
Reinstalling macOS with Erase Assistant
Here is a step-by-step guide to securely erasing your Mac’s internal drive and reinstalling macOS using Erase Assistant:
Requirements
- Mac running macOS High Sierra 10.13.4 or later
- Back up any important data on your Mac
- 16GB+ free storage space for macOS install
- Mac firmware password disabled (if enabled)
Prepare for Reinstall
- Connect your Mac to power adapter to prevent shutdown during install
- Backup important data to an external drive or cloud storage
- Sign out of iCloud and Apple ID accounts
- Deauthorize any linked iTunes accounts
Restart in Recovery Mode
- Restart your Mac and hold Command + R keys immediately
- Let go when you see the Apple logo or spinning globe appear
- This boots you into macOS Recovery system
Launch Disk Utility
- Select Disk Utility from the macOS Utilities window
- Continue through any prompts that appear
- Disk Utility will open
Erase and Reinstall macOS
- Select your internal drive (typically named “Macintosh HD”)
- Click Erase in the toolbar
- Choose “Erase Assistant” and click Continue
- Follow prompt to select a macOS reinstall option
- Agree to Terms and Conditions
- Click Continue to allow Erase Assistant to erase then reinstall macOS
Finish macOS Setup
- Follow the onscreen steps to complete the macOS installation
- Set up your user account and preferences
- Reinstall apps and restore data from backup
- Your Mac now has a fresh macOS install!
Conclusion
The “Erase Assistant not supported” error simply indicates your Mac is running an older version of macOS that does not include the feature.
Updating to macOS High Sierra 10.13.4 or later will enable you to use Erase Assistant for a seamless and secure erase and reinstall process.
Alternatively, you can erase the drive using Disk Utility then reinstall macOS manually via internet recovery or a USB installer drive.
Following the steps outlined above will allow you to easily fix the “Erase Assistant not supported” issue and do a fresh macOS install. Just be sure to backup your data first.
| macOS Version | Erase Assistant Supported? |
|---|---|
| High Sierra 10.13.4 or later | Yes |
| Sierra 10.12 or earlier | No |
