| iMac | Target Display Mode | Second Display |
|---|---|---|
| 24‑inch and 27‑inch, 2009 and 2010 | Yes, with a Mini DisplayPort cable | No: it can’t run macOS 12.3 |
| 2011 to mid 2014 | Yes, with a Thunderbolt cable | No: it can’t run macOS 12.3 |
| Retina 5K, late 2014 and mid 2015 | No | No: it can’t run macOS 12.3 |
| Late 2015: 21.5‑inch, Retina 4K and Retina 5K | No | Yes |
| 2017 to 2020, and iMac Pro | No | Yes, over Thunderbolt 3 |
| 24‑inch with Apple silicon | No | Yes, over Thunderbolt |
Every iMac that can be a display needs macOS 12.3 Monterey or later. Without a Thunderbolt connection, Wi‑Fi and Ethernet work too, with a compressed picture. Use Wi‑Fi or Ethernet
Late 2015 iMacs
Their ports are Thunderbolt 2. Apple’s Thunderbolt 3 (USB‑C) to Thunderbolt 2 Adapter and a Thunderbolt 2 cable connect them to a newer Mac. We haven’t tested that connection yet.
Intel iMacs
We haven’t measured yet how smoothly older and Intel Macs show the lossless picture. The speed test recommends the quality your two Macs can keep up. Older Macs and Intel iMacs
The Mac you work on
It needs macOS 14 Sonoma or later. Apple: Macs that run macOS Sonoma