How to Remove Legacy System Extension on Mac? Step by Step

How do I identify and remove legacy system extensions Catalina warned me about? I tried the uninstaller program, but I don't think it removed everything. - Apple Community

Would you happen to know how to remove legacy system extensions on Mac? As mentioned above, many people don't know how to identify and remove legacy system extensions on their Mac. Whether you know it or not, this article provides an explanation of legacy system extension and the methods to remove legacy system extension.

What is legacy system extension?

Legacy system extension refers to an older type of kernel extension (KEXT) in macOS, used to enable specific hardware or software functionalities. These extensions can interact directly with the macOS kernel to support functions such as external device drivers, networking tools, virtualization software, and antivirus programs.

However, as technology evolves, legacy system extensions are being gradually phased out. Starting with macOS Catalina, Apple introduced System Extensions and DriverKit as replacements for traditional KEXTs.

As a result, if you are using software that relies on legacy system extensions, macOS (from Catalina or later) may display a warning, notifying you that these extensions will not be supported in future macOS versions.

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How to remove legacy system extension on Mac?

Fix1. Uninstall Associated Software

Legacy system extensions are usually loaded by third-party applications, such as hardware drivers, virtualization tools, or antivirus programs. Uninstalling these applications removes the extensions.

You can do this by opening Finder, navigating to the Applications folder, and locating the software associated with the Legacy system extension. Then, drag the application to the Trash, or use the software's uninstaller if available.

Fix2. Remove legacy system extension through iBoysoft DiskGeeker for Mac

iBoysoft DiskGeeker for Mac is a professional disk management tool designed to help users easily manage disks, optimize storage space, and improve system performance. It supports managing connected disks, including internal hard drives, external hard drives, SD cards, etc.

It can scan unnecessary files on your system, including caches, log files, application leftovers, and legacy system extensions. After the scan, you can view the size and names of these files, then selectively delete them based on your needs.

Here's how to do it:

As you can see, just a few simple steps can help you remove the legacy system extension on Mac. Share iBoysoft DiskGeeker for Mac with your friends if you find it helpful!

Fix3. Manually Remove legacy system extension

Most legacy system extensions are stored in /Library/Extensions/ and /System/Library/Extensions/.  So, you should open Finder, click Go > Go to Folder, and manually enter these two paths to search for files related to legacy system extensions (typically with the .kext extension).
 

Once you find the unnecessary extension files, drag them to Trash. The system may prompt you to enter your administrator password, after entering it, click OK.

Since legacy system extensions interact directly with the kernel, you should rebuild the kernel cache to ensure system stability after deletion. Open your Terminal and enter the following command, then press Enter to rebuild the cache:

sudo kextcache --clear-staging

After these steps, you can restart your Mac to ensure the changes take effect.

How do you find legacy system extensions on Mac?

In addition to searching for legacy system extensions in /Library/Extensions/ and /System/Library/Extensions/, you can also find them in the System Report and through Terminal.

The System Report is a tool provided by macOS that allows users to view detailed information about their hardware, software, and network configuration.  In the System Report, there is a section called Software, which lists software-related information, including Kernel Extensions.  Through the System Report, you can view the kernel extensions currently loaded on your system (including legacy system extensions) and their status and details.

To check the installed legacy system extensions, open the System Report, then select Extensions under the Software section in the left sidebar.  In the list on the right, you will see all the kernel extensions installed on the system (including legacy system extensions).  If a kernel extension is outdated, it is typically marked as Legacy or Outdated, and the version information may provide a related warning.

Of course, you can also use Terminal commands to view the loaded extensions.

Share this article if you have successfully removed the legacy system extension on Mac.