How To Change The Virtualbox Guest macOS Virtual Machine Screen Resolution

After installing macOS on VirtualBox virtual machine, when I start it, I found the screen resolution is too low to display the whole screen bigger. So I need to change the macOS virtual machine’s screen resolution to make the screen fully fill the virtual machine’s window. This article will tell you how to do it.

1. How To Get The Current macOS Screen Resolution.

1. Start the VirtualBox macOS virtual machine.
2. Click the top left corner Apple Logo —> System Preferences… menu item to open the System Preferences dialog window.
3. Click the Displays icon in the above window.
4. Click the Display tab, then click the Scaled radio button.
5. You can see the current macOS screen resolution values there.

2. How To Change The VirtualBox macOS Virtual Machine’s Screen Resolution.

1. Power off the macOS virtual machine.
2. Run the command cmd to open a dos window.
3. Go to the VirtualBox installed directory with the cd command.
4. Then run the below 3 commands in the dos window.

   C:\Program Files\Oracle\VirtualBox>VBoxManage setextradata "macOS" CustomVideoMode1 1920x1080x32
   
   C:\Program Files\Oracle\VirtualBox>VBoxManage setextradata "macOS" "GUI/CustomVideoMode1" 1920x1080x32
   
   C:\Program Files\Oracle\VirtualBox>VBoxManage setextradata "macOS" VBoxInternal2/EfiGopMode 5
   
   C:\Program Files\Oracle\VirtualBox>VBoxManage setextradata "macOS" VBoxInternal2/EfiGraphicsResolution 1920x1080
   

5. There are 5 values for the VBoxInternal2/EfiGopMode.

   0 – 640×480
   1 – 800×600
   2 – 1024×768
   3 – 1280×1024
   4 – 1440×900
   5 – 1920×1200

6. Close the VirtualBox Manager window and restart it.
7. Start the macOS virtual machine again, now you will find the screen resolution has been changed.
8. My VirtualBox version is 6.1.30 r148432 (Qt5.6.2), My macOS version is macOS Catalina 10.15.7, My host OS is Win10.

3. How To Make VirtualBox macOS Virtual Machine Screen Full Fill The Virtual Machine’s Window.

1. Although the macOS virtual machine’s screen resolution has been changed, you may still find it is not good to operate.
2. Because the virtual machine’s screen may be wider or higher than the virtual machine window’s size, you have to scroll the scroll bar to operate the macOS apps.
3. To fix this issue, you just need to start the macOS virtual machine, then click the View —> Scaled Mode menu item on the virtual machine’s top menu bar.
4. Then it will popup a dialog, read this dialog carefully, it tells you how to exit the scaled mode ( press the Host Key + C), on Windows the host key is the Right Ctrl key, on macOS the host key is Left Command key.
5. Click the Switch button on the dialog, then you can see the macOS virtual machine’s screen will be changed to fit the virtual machine’s window size.
6. You can press the host key + C to change the macOS virtual machine’s screen mode between scaled mode and normal mode.
7. Do not check the Do not show this message again checkbox in the popup switch dialog, this can make you remember the toggle hotkey.