Use a 2010 iMac as a second monitor.
Yes. A 2010 iMac can be a second screen for any Mac on macOS 14 or later with Encore, free, over Wi‑Fi or a cable (Gigabit Ethernet). Apple's Target Display Mode can't do this with a Mac from 2020 or later.
- Models
- iMac (21.5-inch, Mid 2010), iMac (27-inch, Mid 2010)
- Newest macOS
- macOS 10.13 High Sierra
- Runs Encore Receiver
- Yes
- Cable
- Gigabit Ethernet
- Expected picture
- Up to the panel's size, 30 to 60 fps (expected)
- Target Display Mode
- 27-inch only, Mini DisplayPort (needs a Mac from 2019 or earlier)
- AirPlay to Mac
- No
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What works
- An extra desktop: drag windows onto the iMac as onto any monitor.
- The iMac's own keyboard and mouse can control your Mac. Press Control-Option-Command-Esc on the iMac to switch back.
- Your Mac's sound can play on the iMac's speakers, on one or several iMacs at the same moment.
- More than one iMac at once, each with its own Connect button.
- When it isn't a screen, the iMac can show StandBy: a clock, the weather and your calendar.
Expected picture: up to the panel's size, 30 to 60 fps. We are still checking the picture model by model, so treat this as expected, not measured.
Which app goes on the iMac
The 2010 iMac runs up to macOS 10.13 High Sierra. Encore Receiver needs macOS 10.13 High Sierra or later, so it runs on this iMac. Your Mac needs macOS 14 Sonoma or later, Apple silicon or Intel.
Which cable
Your iMac has a Gigabit Ethernet port and no Thunderbolt, so Ethernet is the way. You need nothing for Wi‑Fi. A cable is optional and helps most with full-screen video. Whatever you buy, the whole connection must handle at least 400 Mbit/s: Gigabit (10/100/1000) Ethernet or Thunderbolt, never a 10/100 adapter.
Gigabit Ethernet
- A USB-C to Gigabit Ethernet adapter for your Mac. It must say Gigabit or 10/100/1000. Skip this if your Mac has an Ethernet port.
- A Cat6 Ethernet cable (Cat5e also works), long enough to reach the iMac.
- Plug the cable into the Ethernet port on the back of the iMac.
Up to 1000 Mbit/s: well above the 400 Mbit/s for high quality.
Target Display Mode on the 2010 iMac
Only the 27-inch Mid 2010 iMac, over a Mini DisplayPort cable. The 21.5-inch Mid 2010 is not on Apple's list.
Whatever the iMac, Apple requires the Mac that connects to be introduced in 2019 or earlier and to run macOS Catalina 10.15.8 or earlier. So a MacBook, Mac mini or iMac with Apple silicon can't use Target Display Mode. Source: Apple's support page.
AirPlay to Mac
No. Receiving AirPlay on a Mac needs an iMac from 2019 or later on macOS 12 Monterey or later.
Other ways
Paid apps, a capture card or a display driver board are other routes, each with its own iMac range. We compared them all, with sources, in every way to use an old iMac as a monitor. Why Apple's own option ended: Target Display Mode explained.
Questions about the 2010 iMac
Can a 2010 iMac be a monitor for an M1, M2, M3 or M4 Mac?
Yes, with Encore, over Wi‑Fi or a cable. Target Display Mode can't, because Apple requires the connecting Mac to be from 2019 or earlier on macOS Catalina or older.
Does the 2010 iMac support Target Display Mode?
Only the 27-inch Mid 2010 iMac, over a Mini DisplayPort cable. The 21.5-inch Mid 2010 is not on Apple's list.
Which cable connects a Mac to a 2010 iMac?
Your iMac has a Gigabit Ethernet port and no Thunderbolt, so Ethernet is the way. The connection must handle at least 400 Mbit/s, so Gigabit Ethernet or Thunderbolt. Wi‑Fi works without any cable.
Will the 2010 iMac's keyboard, mouse and speakers work with my Mac?
Yes. The iMac's keyboard and mouse can control your Mac, and your Mac's sound can play on the iMac's speakers.
Is it free?
Yes, Encore is free during early access, with no account, no ads and no tracking.