Luna Display lets you wirelessly use your Mac as a second Windows monitor

Sometimes you just need more screen space. You can always buy a portable monitor, but what if you could just use the systems you already have at home, whether they’re running Windows or macOS?

Luna Display is a product from Astropad that lets you turn your iPad into a second wireless display. The $130 offer uses a dongle and works with Windows PCs and Macs. Its headless mode turns the iPad into the primary display of a Mac Mini or Mac Pro.

Announced this week, the Luna Display 5.1 update adds even more features. The dongle can now be used with any Apple computer, not just an iPad, to provide a second display for your Windows PC or Mac.

You’re not limited to Apple desktops or laptops either; Luna Display now supports adding a 4K or 5K screen to your computer as a second display. This means you can connect a 24″4.5K (4480×2520) iMac or a 27″5K (5120×2880) iMac to your Windows PC or Mac.

However, there are some caveats. If you plan to connect a Mac 4K or 5K, the machine must have at least macOS Big Sur installed. Any 5K screen connected to your Windows PC will be capped at a refresh rate of 30Hz, which is half the usual (60Hz). If you’re using a Mac with Big Sur or later, the refresh rate bumps up to 45Hz. And if you connect “only”a 4K screen, your refresh rate will be 60Hz, whether the display is connected to a Windows or Apple system.

Other additions with the Luna Display 5.1 update include support for the Apple Magic Keyboard and trackpad with an iPad connected to Luna Display. Again, this feature works whether the iPad is connected to a Mac or PC.

Please note that to use Luna Display in general, you must have a system running 64-bit Windows 10 build 1809 or later or macOS 10.11 El Capitan or later as your primary PC. The iPad must be running iOS 12.1 or later and you will need either 802.11n Wi-Fi or an Ethernet connection.

Since Apple and Windows have historically lived in such different camps, it’s good to see the product bring more platform agnostic for those who aren’t fully committed to one side.