Yes, an old iMac can be a monitor for a Mac mini.
With an app, not Command-F2.
Yes. An Intel iMac from Late 2009 to 2020 can be a screen for a Mac mini with M1, M2 or M4. You need an app such as Encore. Target Display Mode can't do it, because Apple's rule excludes every Mac with Apple silicon. Every Mac mini has an Ethernet port, so the simplest cable is one Cat6 cable to the iMac.
Can I use an iMac as a monitor for a Mac mini?
Yes, if the iMac is an Intel model from Late 2009 to 2020. The Mac mini sends its picture through software, and the iMac shows it as an extra display. Older iMacs from 2007 to Early 2009 work with Encore Receiver Legacy, at a smaller picture of about 1440 x 900.
The Mac mini needs macOS 14 Sonoma or later. The iMac needs macOS 10.13 High Sierra or later for Encore Receiver.
A Mac mini is a good match for this. It sits on the desk next to the iMac, so a short cable is easy. And it has no screen, keyboard or speakers of its own, which the iMac can supply.
Why Command-F2 doesn't work with an M1, M2 or M4 Mac mini
Command-F2 starts Target Display Mode, Apple's old way to use an iMac as a monitor. Apple's support page sets the rule. The Mac that connects must be introduced in 2019 or earlier, on macOS Catalina 10.15.8 or earlier.
No Mac mini with Apple silicon meets that rule. People tried anyway. In a MacRumors thread from 2020, an M1 Mac mini went to a 2011 iMac through Apple's adapter. The result was "Nothing Happened". Encore vs Target Display Mode covers the full rules and the one case where the old route still wins.
Which iMacs work with a Mac mini?
Every Intel iMac from Late 2009 to 2020. What changes by year is the newest macOS and the cable you can use. On the iMac, open the Apple menu and choose About This Mac to see your model.
| iMac | Newest macOS | Cable from a Mac mini |
|---|---|---|
| Late 2009 and 2010 | 10.13 High Sierra | A Cat6 Ethernet cable. These iMacs have no Thunderbolt. |
| 2011 to 2013 | 10.13 High Sierra (2011), 10.15 Catalina (2012, 2013) | A Cat6 cable, or Apple's Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter and a Thunderbolt cable |
| 2014 and 2015 | 11 Big Sur or 12 Monterey | A Cat6 cable, or the same adapter and a Thunderbolt 2 cable |
| 2017 | 13 Ventura | One Thunderbolt 3 or 4 cable, or a Cat6 cable |
| 2019 | 15 Sequoia | One Thunderbolt 3 or 4 cable, or a Cat6 cable |
| 2020 | 26 Tahoe | One Thunderbolt 3 or 4 cable, or a Cat6 cable |
Apple released no new iMac in 2016 or 2018. The full table, with every model, is on the compatibility page.
A 2017 iMac is a typical case. It has Thunderbolt 3 ports, just like the Mac mini, so one cable is enough. The 2017 iMac page shows what that looks like for one model year.
Which Mac mini ports to use
Apple's tech specs list these ports on the Mac mini models with Apple silicon.
| Mac mini | Thunderbolt | Ethernet |
|---|---|---|
| M1, 2020 | Two Thunderbolt / USB 4 ports | Gigabit, 10Gb as an option |
| M2, 2023 | Two Thunderbolt 4 ports | Gigabit, 10Gb as an option |
| M2 Pro, 2023 | Four Thunderbolt 4 ports | Gigabit, 10Gb as an option |
| M4, 2024 | Three Thunderbolt 4 ports, on the back | Gigabit, 10Gb as an option |
| M4 Pro, 2024 | Three Thunderbolt 5 ports, on the back | Gigabit, 10Gb as an option |
Two things stand out. First, every one of them has an Ethernet port. You need no adapter for Gigabit Ethernet, only a cable.
Second, on the 2024 Mac mini, the two USB-C ports on the front are USB 3, up to 10Gb/s. Apple lists the Thunderbolt ports on the back only. Plug a Thunderbolt cable into a back port.
Cable or Wi-Fi with a Mac mini?
Use a cable if the iMac is your everyday monitor. Encore needs at least 400 Mbps between the two Macs for the sharp, lossless picture. Gigabit Ethernet gives up to 1000 Mbps, and Thunderbolt several Gbit/s.
The slowest part of the path sets the speed. Run the cable straight from the Mac mini to the iMac, or through a router or switch with Gigabit ports. Many older routers have 100 Mbps ports, which is not enough.
Wi-Fi works with nothing to buy. But the picture is always lower quality than on a cable, especially off 5 GHz. The iMac's keyboard and mouse also need a cable. The cable guide lists the parts and the traps for every iMac.
Ultra, the mode that sends every frame as ProRes 4444, runs only over a cable. On a 1080p iMac, Gigabit Ethernet is enough for it. On larger panels it needs Thunderbolt, at up to 2560 x 1440. Encore offers it only when the iMac can decode it in time.
How to set it up
- Set up the Mac mini first.Encore is an app on the Mac mini, so you install it with the Mac mini running. A TV or monitor on its HDMI port will do for this step.
- Install both apps.Encore on the Mac mini and Encore Receiver on the iMac. Both are on the download page.
- Connect the cable.Ethernet or Thunderbolt, from the table above.
- Pair once.Type the 4-digit code from the iMac's screen into Encore on the Mac mini. From then on, the iMac connects by itself.
- Arrange the display.The iMac appears in System Settings, Displays, like any monitor. Drag windows across.
What you get, and what you don't
- Keyboard and mouse: over a cable, the iMac's own keyboard and mouse can control the Mac mini. Press Control-Option-Command-Esc on the iMac to switch back.
- Speakers: the Mac mini's sound can play on the iMac's speakers.
- Several iMacs: one Mac mini can drive more than one iMac, each with its own row in the app.
- Retina iMacs: a 4K or 5K iMac gets sharp text at up to 2560 x 1440, scaled to the panel. That is not native resolution.
- Camera and microphone: using the iMac's camera and microphone from your Mac is coming soon, over a cable.
- Latency: Encore has not published latency figures yet. We will publish measurements per iMac model.
When you stop working, the iMac doesn't go dark. StandBy turns it into a clock with the weather and your calendar. It can also play AirPlay music.
Is an old iMac a good Mac mini monitor?
It depends on what you already own. A used iMac is large and draws more power than a modern monitor. Apple's power figures list 40 W at idle for a Late 2015 Retina 4K iMac. A 2020 27-inch iMac draws 74 W at idle.
If you are buying a screen from scratch, a new monitor is simpler. If the iMac is already on your desk, a cable and an app turn it into a second screen. You also keep its keyboard, mouse and speakers in use.
The same steps work for a MacBook. Use an old iMac as a monitor for a MacBook covers the laptop side, including the USB-C adapters a MacBook needs.
Questions
Can I use an old iMac as a monitor for an M1 Mac mini?
Yes, with an app such as Encore, over a cable or Wi-Fi. It works with any Intel iMac from Late 2009 to 2020, and with any Mac mini on macOS 14 or later.
Does Target Display Mode work with a Mac mini?
Only with a Mac mini introduced in 2019 or earlier, on macOS Catalina 10.15.8 or earlier. No Mac mini with M1, M2 or M4 qualifies, according to Apple.
Which cable connects a Mac mini to an iMac?
A Cat6 Ethernet cable from the Mac mini's Ethernet port to the iMac works with every iMac from Late 2009. For 2011 and later iMacs, Thunderbolt is the faster option.
Can the iMac's keyboard and mouse control the Mac mini?
Yes, with Encore, over a cable. Press Control-Option-Command-Esc on the iMac to switch back.
Can the Mac mini use the iMac's camera and microphone?
Not yet. With Encore, using the iMac's camera and microphone is coming soon, over a cable.
What does Encore cost?
Encore is free during the public beta.