Quick answer:
Use a Mac as a second display for your primary Mac or PC
Connect via Wi-Fi, USB, Ethernet, or Thunderbolt
M1–M4 Macs supported, but may have external display limits. Check your model's tech specs under "Display Support".
Mac Mini M4/Mac Studio: Use rear ports only when plugging in the Luna hardware
🖥️ A Mac mini or Mac Studio can be set up in screenless configurations using Luna Display. Find our setup guide for Headless Mode here.
📶 Connecting over Wi-Fi
Connect both Macs to the same Wi-Fi network.
They must be on the same network to find each other. You can also use an Ethernet or Thunderbolt cable instead.
Open the Luna Primary app on your main computer.
This is the Mac or PC where the Luna hardware is plugged in. The icon is a grey and white cat.
Make sure permissions are enabled:
For macOS Mojave: Enable Accessibility
For macOS Catalina or later: Enable Screen Recording
💡 Luna never saves or records your screen.
Open the Luna Secondary app on the Mac you want to use as a second display. The icon is a black and grey cat.
Both computers should automatically connect!
🔌 Using USB, Ethernet, or Thunderbolt
You can also connect your computers directly with a Ethernet, Thunderbolt, or USB cable. Luna hardware must still be plugged into your primary Mac or PC.
Important notes:
USB connections are only compatible with Mac-to-Mac modes running macOS 10.15 or later.
Ethernet is recommended for PC-to-Mac mode, as Thunderbolt has proven to be more unreliable with PC setups.
🔗 Manual Connect
🤔 When should I use Manual Connect?
🤔 When should I use Manual Connect?
Manual Connect is most commonly used in two situations:
Wi-Fi connections: When devices are on the same network but still aren't connecting automatically or you have Public Mode turned on, Manual Connect allows you to enter a code to link them directly.
Wired connections: When using USB, Ethernet, or Thunderbolt and the connection doesn't establish on its own, Manual Connect is a helpful fallback to force the connection manually using your cable's IP address.
If your devices are having trouble discovering each other, Manual Connect is a quick and reliable way to get them linked.
📝 How to use Manual Connect
📝 How to use Manual Connect
Choose "Manual Connect" in both Luna apps.
Look for the four-part code in the Luna Primary app.
The code on the Secondary Mac will have missing digits.
Complete the code by entering the missing digits into the Secondary Mac. You can also delete the pre-populated numbers and enter the IP of your choosing manually.
Tap "Connect" on the Secondary Mac. You're all set!
🔧 Troubleshooting
🔧 Troubleshooting
If your computers don't connect automatically:
Make sure both are on the same Wi-Fi network
Confirm both are on the same Wi-Fi band (2.4GHz or 5GHz)
Check that both apps are open and running
Try Manual Connect
Try a wired connection (USB, Ethernet, or Thunderbolt): How to connect with a cable
Verify that your primary Mac's specifications support external monitors by checking Apple's official documentation.
🛠️ Gather troubleshooting details such as device models, macOS versions, number of external monitors, and types of connections (e.g., USB-C or HDMI) for customer support assistance.