Can’t wait for Universal Control? Share your keyboard and mouse across Macs and PCs now with Barrier

Longing for universal control? Want to use a single keyboard and mouse on multiple Macs or even PCs? You can do this with Barrier, a free virtual KVM switch that lets you share a keyboard and mouse between computers by simply dragging your mouse pointer to the other computer screen. And you even have a shared clipboard that allows cross-platform copy and paste between Mac, Windows or Linux.

Barrier works great, so if you’ve been waiting for Universal Control on macOS Monterey and are disappointed by its delay, this is essentially the same capability offered through an open-source project.

While Universal Control, macOS Monterey’s tentpole feature that allows sharing a keyboard and mouse across multiple Macs and iPads, is now delayed until macOS 12.3 and iPadOS 15.3, you don’t have to wait until then to start sharing a individual keyboard to begin mouse between Macs and also PCs. Barrier now offers this capability, and not only does it work to share a keyboard and mouse between multiple Macs, it also supports Windows and Linux computers, even with a shared clipboard. Unlike Universal Control, it’s not available for iPad, but if you’re a Mac and PC user, you should really appreciate the cross-platform capabilities on offer there.

Barrier is a little technical, but it’s pretty easy to set up and work with if you stick with it, especially on the Mac thanks to Bonjour. Barrier is open source software and is not verified by Apple with Gatekeeper. So if that makes you uncomfortable, you should probably skip Barrier entirely.

How to share keyboard and mouse on Macs/PCs with Barrier

You should make sure that the computers you want to share a mouse and keyboard with are all on the same network, and that you switch back and forth between the different Macs during the initial setup.

  1. Get the latest version of Barrier here (DMG for Mac, exe for Windows) – download this on any computer you want to use a keyboard and mouse with
  2. Copy Barrier from the DMG (or install using the exe on Windows) to your /Applications folder on each Mac you want to use this on, then right-click on Barrier.app and choose Open ‘ to bypass Gatekeeper on any Mac
  3. On all Macs, select “Open System Preferences” and authenticate to allow Barrier to control the Macs*
  4. Allow Barrier access to control Mac

  5. On the Mac with the keyboard and mouse you want to share (the “server Mac”), choose Server on the Set Up Barrier screen, then choose Done.
  6. Select Server as the setup for the Mac you want to share keyboard and mouse on

  7. On the Mac or PC connected to the server Mac to use its mouse/keyboard (the “client Mac”), choose Client, then Done.
  8. On the server Mac, wait a moment and Barrier should automatically detect the Mac wanting to connect via Bonjour, then just click the alignment for where you want the client Macs to be
  9. Choose placement of Macs or PCs with Barrier

  10. The server Mac should then be set up and ready to go, with the screen looking something like this:
    Server Mac Barrier Configuration
  11. On the client mac, confirm that you want to connect to the mac / trust the sha fingerprint to connect to the server mac
  12. Repeat this process on any other Macs you want to connect to the server Mac for keyboard and mouse sharing
  13. For Windows PC clients, everything is the same apart from auto-bonjour connection. So instead provide the server Mac IP address and connect manually

Everything should work now, and you can easily drag your mouse and keyboard across the Macs (or PCs) simply by moving your cursor to where you aligned the other computers during setup.

You can use the clipboard to copy and paste text or images between computers.

Troubleshooting when Barrier is not working, fix “Barrier ERROR: SSL certificate does not exist” error.

If things aren’t working, on the server Mac open the Barrier menu item and select “Show Log” to get an error message log of what’s going on, which should give you a good idea of ​​what’s going wrong.

If you see an error message that reads something like this:
openERROR: ssl certificate doesn't exist: /home/user/.var/app/com.github.debauchee.barrier/data/barrier/SSL/Barrier.pem

Then you need to manually generate a private security key for Barrier by running the following commands in Terminal.app:

First change your directory to the Barrier SSL folder:
cd ~/Library/Application Support/barrier/SSL

Now generate a security key:
openssl req -x509 -nodes -days 365 -subj /CN=Barrier -newkey rsa:4096 -keyout Barrier.pem -out Barrier.pem

Back in the Barrier app on the server Mac, click Stop and then click Start Barrier Server to load the private key.

The client Mac(s) or PC(s) should now ask a security question showing the generated fingerprint and asking you “Do you trust this fingerprint?” If it matches, select “Yes” to log in to the Barrier to connect server mac.

Trust this certificate security question barrier

You can also try to connect manually by providing the IP address of the server Mac directly. If you’re not sure what that is, you can get the IP address on the Mac that’s acting as a barrier server from the network settings.

Client connection to the barrier server

Barrier also works across multiple OS versions, in the setup shown here I’m running Barrier on multiple Macs running macOS Big Sur and macOS Monterey with ease, but you can set this up with Windows 11, Windows 10, Linux, and just about anything else that uses Barrier executes

* If you’re not comfortable with having unvetted, third-party, open-source software controlling your Macs, you can’t use Barrier. Use at your own risk and make your own security/privacy decisions based on your use case and needs.

So don’t wait any longer for Universal Control, use Barrier to share a keyboard and mouse across multiple Macs (or even PCs) now. Sure, you can’t run it on an iPad, but you can still use Sidecar on the iPad to turn it into a different Mac display if you want to include your iPad in the mix.

For the curious, Barrier was separated from and is based on the Synergy open source project’s codebase before Synergy became a paid product offering. If you’re a long-time reader of OSXDaily, you might remember that we covered Synergy (or a similar app called Teleport back in the day too) back in 2012. And yes, that means if you like the idea of ​​Barrier but want official support, you can Check out Synergy and buy this app instead, which also offers cross-platform compatibility. If you are exclusively Windows user, there is also mouse without limits but this does not work with a Mac or Linux machine. Finally, ShareMouse is another paid solution that offers similar KVM features if you want to check that out too.

Have you got Barrier working to share your keyboard and mouse across multiple Macs and even Windows PCs or Linux machines? Will you be using this instead of Universal Control or until Universal Control comes out? Let us know your thoughts and experiences in the comments.

About Willie Ash

Check Also

Ubuntu Core brings real-time processing to Linux IoT

Most of you are familiar with Ubuntu as a desktop operating system; others know it …