A Mac mini has no screen of its own, and an old MacBook in a drawer has a good one. A cable alone doesn’t make a MacBook a monitor; an app does. Install Second Display on both Macs. Your Mac mini then gets an extra display, as if you had plugged in a monitor, and shows it on the MacBook.
What you need
| Mac | Needs |
|---|---|
| Mac mini | macOS 14 Sonoma or later, and a Thunderbolt port (⚡︎) for the sharpest picture. |
| MacBook | macOS 12.3 Monterey or later, Intel or Apple silicon. No account and no Screen Recording permission. |
| Between them | A Thunderbolt cable, or both Macs on the same Wi‑Fi or Ethernet network. |
Not sure your Mac runs macOS 14? Apple lists the models: Apple: Macs that run macOS Sonoma. Use a MacBook or another Mac as a display · What you need
How they connect
- Thunderbolt cable. The sharpest picture: exactly what your Mac draws, at 60 frames per second. Use a port with the ⚡︎ symbol on both Macs. Thunderbolt: which cable and which port?
- Wi‑Fi or Ethernet. Put both Macs on the same network and the picture adapts to the connection, slightly softer than over a cable. Use Wi‑Fi or Ethernet
- A USB‑C cable without Thunderbolt. Works too, with a slightly softer picture. A USB‑C cable without Thunderbolt
Set it up
Download Second Display and open it on both Macs.
On the MacBook, choose Use this Mac as a display.
On the Mac mini, choose This is the Mac I work on, and allow Screen Recording (and, on macOS 15 or later, Local Network access).
Plug in the cable, or join the same network. The two Macs find each other on their own, and a five-second speed test picks the best quality they can keep up with. Older Macs
Sign in with email, Apple or Google. This starts the 7-day free trial, with no payment details.
Then click Arrange Displays… in the Second Display menu and drag the MacBook to where it stands next to your other display. Second Display remembers the position. Arrange your displays
Using it every day
- Keyboard and mouse. Keep the Mac mini’s keyboard and mouse. Its pointer moves onto the MacBook as onto any display. Keyboard, mouse and sound
- Sound. The MacBook shows up as a speaker on the Mac mini. Sound through the MacBook’s speakers
- On battery. Both Macs stay awake while a picture is shown. Sleep, wake and the lock screen
Prefer an iMac?
An iMac from late 2015 on works the same way, with a bigger screen. Use an iMac as a monitor for your Mac mini
Questions
Can I use an old MacBook as a second screen for my Mac mini?
Yes. A MacBook Air or MacBook Pro from early 2015 on, with Intel or Apple silicon, becomes an extra display for your Mac mini. It needs macOS 12.3 Monterey or later.
What cable do I need?
A Thunderbolt cable, in a port with the ⚡︎ symbol on both Macs, gives the sharpest picture. Not every MacBook has a Thunderbolt port, and no cable works too: put both Macs on the same Wi‑Fi or Ethernet network.
Does it work with a Mac Studio or an M4 Mac mini?
Yes. The Mac you work on can be any Mac mini or Mac Studio that runs macOS 14 or later, M4 models included.
Can I use AirPlay to show my Mac mini on a MacBook?
A MacBook introduced in 2018 or later can receive AirPlay, which Apple describes as streaming and mirroring. Second Display makes the MacBook an extra display of the Mac mini instead.
Which keyboard and mouse do I use?
The Mac mini’s. Its pointer moves onto the MacBook as onto any display, and its keyboard types into the windows there. The MacBook’s own keyboard and trackpad stay with the MacBook.
What happens when the MacBook is on battery?
While it waits for your Mac mini, a MacBook on battery sleeps as usual. While it shows a picture, both Macs stay awake, on battery too. Close the lid and the connection ends; the Mac mini connects again when the MacBook wakes.