Encore vs Duet Display.
For an old iMac as a monitor.
Duet is a subscription that also covers iPads, Android tablets and Windows PCs. It has a page for using an iMac as a second monitor, but it names no iMac years. Encore is built only for this job. Encore is free during the public beta. Pick Duet if you want one app for tablets and computers, and if a subscription is fine. Pick Encore if your iMac is the point, you want a known list of supported iMacs, and you would rather not subscribe.
Who should pick which
- Pick Duet if you also want an iPad, Android tablet or Windows PC as a screen, or you need a Mac on an older macOS: Duet's site lists a build for macOS 10.13 to 10.15.
- Pick Encore if your goal is the old iMac and you want a clear list of supported models (Late 2009 to 2020, and 2007 to Early 2009 with Encore Receiver Legacy), a one-off price, and the iMac's keyboard and mouse over a cable.
Side by side
| Encore | Duet Display | |
|---|---|---|
| Price | Free during the public beta | US App Store: Starter $3.99 a month or $39.99 a year, Air $5.99 or $49.99, Pro $7.99 or $79.99 |
| Your Mac | macOS 14 or later, Apple silicon or Intel | Duet lists macOS 11 or later for Apple silicon, and a separate build for macOS 10.13 to 10.15 |
| Oldest iMac | Late 2009 (macOS 10.13); 2007 to Early 2009 with Encore Receiver Legacy | Not stated. Duet's iMac page names no years or models |
| Account | None | Same account on both Macs |
| Connection | Wi-Fi, Gigabit Ethernet or Thunderbolt | Wireless, or a Thunderbolt cable between two Macs on macOS 12.3 or later |
| Plan needed for a Mac as a display | One licence | Not stated on Duet's pages |
| Picture and speed | Sharp, lossless picture over a cable; Retina iMacs at up to 2560 x 1440; latency not published yet | "60 frames per second with zero lag" (Duet's claim, no figures published on that page) |
| iMac keyboard and mouse control your Mac | Yes, over a cable | Not listed |
| Other devices as a screen | No | iPad, iPhone, Android, Windows |
| Smart display when idle | StandBy clocks, weather, calendar, AirPlay music, Hey Mac | No |
Subscription or one-off
Duet's plans are monthly or yearly. Encore is free during the public beta: every iMac you own, every update, no account. If you only want the iMac as a monitor and a subscription bothers you, that is the simplest reason to pick Encore. If you use Duet's remote desktop or drawing features on an iPad, Duet already pays for itself and the iMac comes with it.
Which iMacs work
This is where the two differ in clarity rather than in features. Duet tells you to install the app on both machines and sign in, and its page does not give an oldest supported iMac. A Mac needs macOS 12.3 or later for Thunderbolt, per that page, which rules out most iMacs before Late 2015 for a wired connection. Encore's list is exact: see compatibility.
Cable or Wi-Fi
Both work over Wi-Fi. Encore over Wi-Fi is always lower quality than over a cable, especially off 5 GHz, and its keyboard and mouse need a cable. For Encore the minimum over a cable is 400 Mbps, which means Gigabit Ethernet or Thunderbolt, on any iMac from Late 2009. Read Wi-Fi or cable for a second screen for the detail.
Where Encore is weaker
Encore has no published latency figure yet. It only works between two Macs, with no iPad or PC. And it needs macOS 14 on your main Mac, while Duet still offers a build for much older systems.
Facts on this page were checked on 9 November 2026 on the linked pages. Speeds are each maker's own figures, not independent measurements. Something out of date? Tell us and we fix it.
Questions
Can Duet use my old iMac as a second monitor?
Duet has a page for exactly this, but it names no iMac years. You install Duet on both machines and sign in with the same account. For a Thunderbolt connection both Macs need macOS 12.3 or later.
Which Duet plan do I need for a Mac as a display?
Duet's pages we checked do not say which plan covers using a Mac as a display. Check the current plan descriptions on duetdisplay.com before you buy.
Does Duet need a subscription?
Duet's App Store listing shows Starter, Air and Pro as monthly or yearly plans. Encore is free during the public beta.
Does Encore work with an iPad?
No. Encore is Mac to Mac only. For an iPad, Apple's Sidecar, Duet or Luna Display fit.